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HomeMy WebLinkAboutRS_SWPPP_Sapphire_on_Talbot_200128_v4Construction Stormwater General Permit (CSWGP) Stormwater Pollution Prevention Plan (SWPPP) for Sapphire on Talbot Prepared for: The Washington State Department of Ecology Northwest Regional Office 3190 160th Ave SE Bellevue, WA 98008 SDP2017-02556 Permittee / Owner Developer Operator / Contractor Troy Schmeil 16805 SE 43rd Court Bellevue, WA 98006 Troy Schmeil 16805 SE 43rd Court Bellevue, WA 98006 TBD Certified Erosion and Sediment Control Lead (CESCL) Name Organization Contact Phone Number TBD TBD TBD SWPPP Prepared By Name Organization Contact Phone Number Edward Mecum Encompass Engineering and Surveying (425) 392-0250 SWPPP Preparation Date 06/13/2019 Project Construction Dates Activity / Phase Start Date End Date Site Grading To Be Determined To Be Determined DEVELOPMENT ENGINEERING Nathan Janders 02/07/2020 Table of Contents LIST OF ACRONYMS AND ABBREVIATIONS ........................................................................................... 3 1.0 PROJECT INFORMATION ..................................................................................................................... 4 2.0 CONSTRUCTION STORMWATER BEST MANAGEMENT PRACTICES (BMPS) .............................. 7 3.0 POLLUTION PREVENTION TEAM ........................................... ERROR! BOOKMARK NOT DEFINED. 4.0 MONITORING AND SAMPLING REQUIREMENTS ................. ERROR! BOOKMARK NOT DEFINED. 5.0 DISCHARGES TO 303(D) OR TOTAL MAXIMUM DAILY LOAD (TMDL) WATERBODIES ... ERROR! BOOKMARK NOT DEFINED. 6.0 REPORTING AND RECORD KEEPING ................................... ERROR! BOOKMARK NOT DEFINED. APPENDIX/GLOSSARY .................................................................. ERROR! BOOKMARK NOT DEFINED. List of Tables 1. Summary of Site Pollutant Constituents 2. Pollutants 3. pH-Modifying Sources 4. Management 5. Team Information 6. Turbidity Sampling Method 7. pH Sampling Method List of Appendices A. Site Map B. BMP Detail C. Site Inspection Form D. CSWGP E. Engineering Calculations List of Acronyms and Abbreviations Acronym / Abbreviation Explanation 303(d) Section of the Clean Water Act pertaining to Impaired Waterbodies BFO Bellingham Field Office of the Department of Ecology BMP(s) Best Management Practice(s) CESCL Certified Erosion and Sediment Control Lead CO2 Carbon Dioxide CRO Central Regional Office of the Department of Ecology CSWGP Construction Stormwater General Permit CWA Clean Water Act DMR Discharge Monitoring Report DO Dissolved Oxygen Ecology Washington State Department of Ecology EPA United States Environmental Protection Agency ERO Eastern Regional Office of the Department of Ecology ERTS Environmental Report Tracking System ESC Erosion and Sediment Control GULD General Use Level Designation NPDES National Pollutant Discharge Elimination System NTU Nephelometric Turbidity Units NWRO Northwest Regional Office of the Department of Ecology pH Power of Hydrogen RCW Revised Code of Washington SPCC Spill Prevention, Control, and Countermeasure su Standard Units SWMMEW Stormwater Management Manual for Eastern Washington SWMMWW Stormwater Management Manual for Western Washington SWPPP Stormwater Pollution Prevention Plan TESC Temporary Erosion and Sediment Control SWRO Southwest Regional Office of the Department of Ecology TMDL Total Maximum Daily Load VFO Vancouver Field Office of the Department of Ecology WAC Washington Administrative Code WSDOT Washington Department of Transportation WWHM Western Washington Hydrology Model Project Information (1.0) Project/Site Name: Sapphire on Talbot Street/Location: 4827 Talbot RD S City: Renton State: WA Zip code: 98055 Subdivision: N/A Receiving waterbody: Springbrook Creek Existing Conditions (1.1) Total acreage (including support activities such as off-site equipment staging yards, material storage areas, borrow areas). Total acreage: 1.79 AC Disturbed acreage: 1.79 AC Existing structures: 1 Single-Family residence and associated outbuildings, paved driveway. Landscape topography: Trees, brush, grass, lawn. Drainage patterns: Site generally sheet flows to the west at 2% to 17%. Existing Vegetation: Trees, brush, grass, lawn. Critical Areas: No known critical areas on or adjacent to the site. List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the receiving waterbody: Bioassessment Table 1 includes a list of suspected and/or known contaminants associated with the construction activity. Table 1 – Summary of Site Pollutant Constituents Constituent (Pollutant) Location Depth Concentration Gasoline Construction Vehicles Concrete Curb, gutter, and sidewalk improvements Onsite Septic Sewer Near existing house Proposed Construction Activities (1.2) Description of site development: The parcel will be subdivided into 20 lots, an access road, shared driveway, and an open space/tree retention/stormwater tract. Description of construction activities: The project site will be cleared and graded prior to the start of construction. The development of the site will include site grading, demolition on all existing structures, and utilities installation. Utilities will include stormwater, sanitary sewer, potable water, and all private utilities. Description of site drainage including flow from and onto adjacent properties. Must be consistent with Site Map in Appendix A: Level 1 Downstream Analysis from the engineering Technical Information Report: A Level 1 Downstream Drainage Analysis was performed October 12, 2018 at around 8:00 AM. The weather was clear and roughly 60°. The site is developed with an existing single-family residence, detached garage and paved driveway. The site is comprised of grasses, trees and shrubs around the boundaries of the property. The eastern portion of the site slopes to the west at 2-17%. Task 1: The area of analysis extends downstream from the site to 1/4 mile downstream. Task 2: Per King county resources, there have been no significant drainage complaints. Task 3: There were no apparent downstream drainage issues. Task 4: The site mostly sheet flows (A) west into a wooded tract, part of the adjacent Ashburn Condominium project. There is an existing level spreader (B) of some sort constructed with the Ashburn collecting and routing at least some of the flows into a 12” pipe system in Ashburn that directs these flows around the detention vault constructed for the Ashburn project (E). This bypass pipe (C) discharges into a wooded ravine (H) about 350’ downstream from the site. Flows from the ravine cross under on the Ashburn streets through a 12” pipe (I), continuing west through more wooded ravine (J) then into the SR-167 storm system (G), about ¼ mile downstream from the site. That portion of runoff from the site (A) that doesn’t drain into the bypass pipe mentioned above drains past the existing level spreader (B) into a wooded area south of the site, then into an inlet pipe (D), about 200’ west of the site. The flows drain though the 12” Ashburn pipe system about ¼ mile before discharging into a large underground detention vault (E). The vault discharges into an overgrown bioswale F) draining south, then west towards the SR-167 storm system (G), a distance of greater than ¼ mile downstream from the site. Description of final stabilization: Final stabilization will include revegetation and landscaping of exposed areas, and paving of roads and sidewalks. Full description can be seen in the landscape plan in the engineering plan sheets. Contaminated Site Information: Proposed activities regarding contaminated soils or groundwater: There are no known contaminated soils on site. Any existing onsite septic sewer system will be removed or abandoned in place as needed. Construction Stormwater Best Management Practices (BMPs) (2.0) The SWPPP is a living document reflecting current conditions and changes throughout the life of the project. These changes may be informal (i.e. hand-written notes and deletions). Update the SWPPP when the CESCL has noted a deficiency in BMPs or deviation from original design. The 12 Elements (2.1) Element 1: Preserve Vegetation / Mark Clearing Limits (2.1.1) The limits of clearing and grading will be marked in several ways around the site depending on the location. Combination high visibility orange/silt fencing will be installed along clearing limits. Several trees are scheduled to be retained on the site. Trees that are within the clearing limits will need to be protected with a tree protection fence. During the clearing effort, the topsoil and duff materials should be kept in a separate stockpile for future use to help promote grass growth during project close out. List and describe BMPs: BMP C101: Preserving Natural Vegetation BMP C103: High Visibility Plastic or Metal Fence BMP C233: Silt Fence Installation Schedules: Marking the clearing limits is one of the first things to be accomplished on the construction site. Prior to any site clearing or grading, areas that are to remain undisturbed during project construction shall be delineated. Once all plat construction is complete, leaving just the residences to be constructed, the clearing limit BMP’s may be removed as approved by the City. Portions of fencing may remain in place if the residence construction is scheduled to begin. Inspection and Maintenance plan: The clearing limits should be observed on a daily basis and thoroughly inspected weekly to ensure they are in place and functioning to protect areas that are not being cleared. Any damaged or missing portions of the clearing limit BMP’s should be repaired or replaced immediately. Responsible Staff: CESCL Element 2: Establish Construction Access (2.1.2) A stabilized construction entrance is proposed for this site. If construction vehicles are observed tracking soil onto the roads, a wheel wash will be installed at one construction access. A gravel construction parking area is proposed for contractor staging. List and describe BMPs: BMP C105: Stabilized Construction Entrance BMP C106: Wheel Wash (if necessary) BMP C107: Construction Road/Parking Area Stabilization Installation Schedules: The stabilized construction entrance should be established at the start of construction for all active access points. The construction road/parking area stabilization should be established after preliminary grading is completed. Inspection and Maintenance plan: The construction entrance will be observed daily for any deficiencies such as dirt or mud covering the rocks. Also, the public roads will be observed on a continual basis during vehicle exiting to ensure no soil deposits are being tracked onto the roadway. If the construction entrance proves inadequate to prevent soil from being deposited onto the roadway, additional measures will be necessary, including street sweeping and the use of a wheel wash for pervasive failures. Other stabilized areas will be inspected regularly, especially after large storm events. Any damaged or missing portions of the site BMP’s should be repaired or replaced immediately. Responsible Staff: CESCL Element 3: Control Flow Rates (2.1.3) Based on the City of Renton’s flow control map, the site falls within the “Flow Control Duration Standard” area matching Forested Site Conditions and is within the Black River Drainage Basin. Therefore engineering must apply the Flow Control Duration Standard which matches the flow duration of pre-developed rates forforested (historical) site conditions over the range of flows extending from 50% of 2-year up to the full 50-year flow AND matches peaks for the 2- and 10- year return periods. Will you construct stormwater retention and/or detention facilities? Yes No A permanent stormwater detention/infiltration vault and associated infrastructure will be constructed on site. This vault has been sized using the 2-year storm and 10-year storm flows. A temporary sediment pond with associated infrastructure will be constructed on site. The temporary sediment pond is sized using the 2-year storm and 10-year storm. Will you use permanent infiltration ponds or other low impact development (example: rain gardens, bio-retention, porous pavement) to control flow during construction? Yes No List and describe BMPs: BMP C207: Check Dams BMP C209: Outlet Protection BMP C240: Sediment Trap BMP C241: Temporary Sediment Pond Installation Schedules: Construction of the BMPs and associated infrastructure is scheduled for the beginning of the project. The measures described above are required throughout construction. Inspection and Maintenance plan: The BMPs should be inspected on a weekly basis to verify that the capacity has not diminished due to sedimentation in such a way that the BMP loses efficiency. Sediment shall be removed from the temporary sediment pond when it reaches 1-foot in depth. Any damaged or missing portions of the site BMP’s should be repaired or replaced immediately. Responsible Staff: CESCL Element 4: Install Sediment Controls (2.1.4) Areas of disturbed soil shall be routed through a temporary sediment pond via a series of temporary intercepter swales. This, in conjunction with the listed BMPs, shall serve to minimize sediment discharges from the site. List and describe BMPs: BMP C233: Silt Fence BMP C240: Sediment Trap BMP C241: Temporary Sediment Pond BMP C250: Construction Stormwater Chemical Treatment (to be implemented only with prior written approval from Ecology) Installation Schedules: Implimentation of silt fencing, sediment traps, temporary sediment pond, and associated infrastructure is scheduled for the beginning of the project. These BMPs shall be functional before other land disturbing activities take place. The measures described above are required throughout construction. Inspection and Maintenance plan: The sediment control facilities should be inspected on a weekly basis to verify that the capacity has not diminished due to sedimentation in such a way that the BMP loses efficiency. Any damaged or missing portions of the site BMPs should be repaired or replaced immediately. Responsible Staff: CESCL Element 5: Stabilize Soils (2.1.5) Soils on site will be stabilized as appropriate through a variety of methods. These BMPs will be implemented when soil is to remain unworked or at the threat of rain throughout the project. Stock piles will be covered with plastic sheeting unless an extended period of storage is expected, in which case the stockpiles should be seeded and covered with mulch and an erosion control net. Runoff from plastic sheeting will be directed into a temporary ditch and conveyed to an appropriate outlet location. Slopes, once in place will be covered with a combination of hydroseeding and mulch. If these stabilizing BMPs prove ineffective, the contractor should improve the cover method with nets and blankets. During the hot summer months, dust control is necessary. This is accomplished by applying water to dry soils routinely. The water should not be applied in a way that creates runoff, however. West of the Cascade Mountains Crest Season Dates Number of Days Soils Can be Left Exposed During the Dry Season May 1 – September 30 7 days During the Wet Season October 1 – April 30 2 days Soils must be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast. Anticipated project dates: Start date: Summer 2019 End date: Fall 2020 Will you construct during the wet season? Yes No List and describe BMPs: BMP C101: Preserving Natural Vegetation BMP C120: Temporary and Permanent Seeding BMP C121: Mulching BMP C122: Nets and Blankets BMP C123: Plastic Covering BMP C140: Dust Control Installation Schedules: Soil Stabilization BMPs will be applied as deemed necessary. Exposed areas should be evaluated and covered to prevent impacts to roadways, drainage ways, or surface waters. Seeding shall be used throughout the project on disturbed areas that have reached final grade or that will remain unworked for more than 30 days. Inspection and Maintenance plan: Soil Stabilization BMPs should be reviewed daily and thoroughly inspected weekly and after each rainfall event to ensure they are functioning appropriately. All deficiencies shall be repaired or replaced in accordance with the number of days exposed soils may be left exposed. Any damaged or missing portions of the site BMPs should be repaired or replaced immediately. Responsible Staff: CESCL Element 6: Protect Slopes (2.1.6) The steepest slopes existing on the site are located in the southeast corner of the construction area. All slopes created on the site will be stabilized upon completion with a combination of hydroseed, mulch and, if necessary, erosion control netting. Hydraulic modeling using WWHM has been attached in Appendix B. Scouring within constructed channels shall be reduced using interceptor dikes and swales in conjunction with check dams. Will steep slopes be present at the site during construction? Yes No List and describe BMPs: BMP C120: Temporary and Permanent Seeding BMP C121: Mulching BMP C122: Nets and Blankets BMP C200: Interceptor Dike and Swale BMP C207: Check Dams Installation Schedules: Slopes are to be protected throughout construction. Inspection and Maintenance plan: Stabilized slopes created during construction should be inspected on a weekly basis and after every rainfall event. Repairs to stabilization BMPs should be made in accordance to the exposed soils schedule. Any damaged or missing portions of the site BMPs should be repaired or replaced immediately. Responsible Staff: CESCL Element 7: Protect Drain Inlets (2.1.7) Catch basin inserts will be installed on all onsite and downstream catch basins. List and describe BMPs: BMP C220: Storm Drain Inlet Installation Schedules: Storm drain inlets are to be installed prior to the start of construction for all existing inlets. Constructed onsite catch basins will be protected prior to the first gravel lift. Inspection and Maintenance plan: All facilities should be inspected weekly and after every rainfall event. BMPs showing 1/3 of their capacity full of sediment should have the sediment removed or the unit replaced. Any damaged or missing portions of the site BMPs should be repaired or replaced immediately. Responsible Staff: CESCL Element 8: Stabilize Channels and Outlets (2.1.8) Channels and culverts will be constructed to divert water to the temporary sediment pond. A permanent drainage system will be constructed to convey flows to the detention/infiltration vault. These features are sized using the WWHM outputs attached in Appendix B. List and describe BMPs: BMP C202: Channel Lining (if necessary) BMP C207: Chek Dams BMP C209: Outlet Protection Installation Schedules: Stabilization BMPs are to be implemented after temporary channels are constructed. Channel lining shall be used if other measures prove insufficient for stabilization. Inspection and Maintenance plan: BMPs shall be monitored for performance and sediment accumulation during and after each runoff event. Sediment shall be removed from check dams when it reaches on half the sump depth. Any damaged or missing portions of the site BMPs should be repaired or replaced immediately. Responsible Staff: CESCL Element 9: Control Pollutants (2.1.9) The following pollutants are anticipated to be present on-site: Table 2 – Pollutants Pollutant (and source, if applicable) Gasoline in vehicles Concrete poured in place Existing onsite sanitary sewer There are no known pollutants contained on the existing site. During construction, the contractor will need to conduct maintenance, fueling, and repair of heavy equipment and vehicles offsite as spills of hazardous materials could result in an environmental event. If a wheel wash is incorporated into the protection plan, the contractor will discharge wheel wash wastewater to a separate on-site treatment system that prevents discharge to surface water, such as closed-loop recirculation or upland land application, or to the sanitary sewer, with local sewer district approval. Concrete will be handled in ways to eliminate concrete, concrete process water, and concrete slurry from entering waters of the state. List and describe BMPs: BMP C151: Concrete Handling BMP C152: Sawcutting and Surfacing Pollution Prevention BMP C153: Material Delivery, Storage and Containment BMP C154: Concrete Washout Area BMP C241: Temporary Sediment Pond BMP C251: Construction Stormwater Filtration Installation Schedules: BMPs will be implemented at the beginning of construction and as needed throughout the project. Concrete washout BMPs shall be in place prior to the commencement of concrete work. Inspection and Maintenance plan: Inspection of the concrete washout area should be done weekly and prior to expected concrete pours. Washout facilities must be cleaned, or new facilities must be constructed and ready for use one the washout is 75% full. Secondary containment facilities should be inspected daily and repaired or replaced as necessary. Contaminated surfaces shall be cleaned immediately following any discharge or spill incident. Any damaged or missing portions of the site BMPs should be repaired or replaced immediately. Responsible Staff: CESCL Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site? Yes No List and describe BMPs: BMP C153: Material Delivery, Storage and Containment Installation Schedules: Containment of hazardous materials will be conducted throughout the duration of construction. Inspection and Maintenance plan: Containment facilities should be inspected daily and repaired or replaced as necessary. Material storage areas shall be kept clean, organized and equipped with an ample supply of appropriate spill clean-up material. Contaminated surfaces shall be cleaned immediately following any discharge or spill incident. Any damaged or missing portions of the site BMPs should be repaired or replaced immediately. Responsible Staff: CESCL Will wheel wash or tire bath system BMPs be used during construction? Yes No List and describe BMPs: BMP C106: Wheel Wash Installation Schedules: Wheel wash systems will be installed if deemed necessary by the contractor when the stabilized construction entrance is not preventing sediment from being tracked onto pavement. Inspection and Maintenance plan: Wheel wash systems will be inspected weekly and repaired as necessary. Wash water should be changed a minimum of once per day. Responsible Staff: CESCL Will pH-modifying sources be present on-site? Yes No If yes, check the source(s). Table 3 – pH-Modifying Sources None X Bulk cement Cement kiln dust Fly ash Other cementitious materials X New concrete washing or curing waters X Waste streams generated from concrete grinding and sawing Exposed aggregate processes Dewatering concrete vaults X Concrete pumping and mixer washout waters Recycled concrete Other (i.e. calcium lignosulfate) [please describe] During this construction activity, the pH levels of stormwater runoff must be monitored. If pH levels exceed 8.5, the level will need to be corrected. The use of CO2 per WDOE standards will rapidly neutralize the water and make it suitable for discharge. List and describe BMPs: BMP C252 High pH Neutralization using CO2 Installation Schedules: pH neutralization using CO2 will be implemented as necessary to correct pH levels in excess of 8.5. Inspection and Maintenance plan: Operators will keep written records related to treatment as detailed in the Stormwater Management Manual for Western Washington. A copy of this record should be given to the client/contractor who should retain the record for three years. Responsible Staff: CESCL Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches, streets, or streams. Excess concrete must not be dumped on-site, except in designated concrete washout areas with appropriate BMPs installed. Element 10: Control Dewatering (2.1.10) Dewatering is not proposed to occur on this site. List and describe BMPs: N/A Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Element 11: Maintain BMPs (2.1.11) All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained and repaired as needed to ensure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMP specification (see Volume II of the SWMMWW or Chapter 7 of the SWMMEW). Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to once every calendar month. All temporary ESC BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be stabilized on-site or removed. Disturbed soil resulting from removal of either BMPs or vegetation shall be permanently stabilized. Additionally, protection must be provided for all BMPs installed for the permanent control of stormwater from sediment and compaction. BMPs that are to remain in place following completion of construction shall be examined and restored to full operating condition. If sediment enters these BMPs during construction, the sediment shall be removed and the facility shall be returned to conditions specified in the construction documents. Element 12: Manage the Project (2.1.12) The project will be managed based on the following principles: • Projects will be phased to the maximum extent practicable and seasonal work limitations will be taken into account. • Inspection and monitoring: o Inspection, maintenance and repair of all BMPs will occur as needed to ensure performance of their intended function. o Site inspections and monitoring will be conducted in accordance with Special Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map. Sampling station(s) are located in accordance with applicable requirements of the CSWGP. • Maintain an updated SWPPP. o The SWPPP will be updated, maintained, and implemented in accordance with Special Conditions S3, S4, and S9 of the CSWGP. As site work progresses the SWPPP will be modified routinely to reflect changing site conditions. The SWPPP will be reviewed monthly to ensure the content is current. Table 4 – Management X Design the project to fit the existing topography, soils, and drainage patterns X Emphasize erosion control rather than sediment control Minimize the extent and duration of the area exposed X Keep runoff velocities low X Retain sediment on-site X Thoroughly monitor site and maintain all ESC measures Schedule major earthwork during the dry season Other (please describe) Element 13: Protect Low Impact Development (LID) BMPs (2.1.13) The proposed project will not incorporate LID BMPs. No protection is required for this BMP. Pollution Prevention Team (3.0) Table 5 – Team Information Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) TBD TBD Resident Engineer Ed Mecum (425) 392-0250 Emergency Ecology Contact TBD TBD Emergency Permittee/ Owner Contact Troy Schmeil (206) 954-4945 Non-Emergency Owner Contact Troy Schmeil (206) 954-4945 Monitoring Personnel TBD TBD Ecology Regional Office Northwest (425) 649-7000 Monitoring and Sampling Requirements (4.0) Monitoring includes visual inspection, sampling for water quality parameters of concern, and documentation of the inspection and sampling findings in a site log book. A site log book will be maintained for all on-site construction activities and will include: • A record of the implementation of the SWPPP and other permit requirements • Site inspections • Stormwater sampling data The site log book must be maintained on-site within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. Numeric effluent limits may be required for certain discharges to 303(d) listed waterbodies. See CSWGP Special Condition S8 and Section 5 of this template. Complete the following paragraph for sites that discharge to impaired waterbodies for fine sediment, turbidity, phosphorus, or pH: The receiving waterbody, Springbrook Creek, is impaired for: Bioassessment. All stormwater and dewatering discharges from the site are subject to an effluent limit of 8.5 su for pH and/or 25 NTU for turbidity. Site Inspection (4.1) Site inspections will be conducted at least once every calendar week and within 24 hours following any discharge from the site. For sites that are temporarily stabilized and inactive, the required frequency is reduced to once per calendar month. The discharge point(s) are indicated on the Site Map (see Appendix A) and in accordance with the applicable requirements of the CSWGP. Stormwater Quality Sampling (4.2) Turbidity Sampling (4.2.1) Requirements include calibrated turbidity meter or transparency tube to sample site discharges for compliance with the CSWGP. Sampling will be conducted at all discharge points at least once per calendar week. Method for sampling turbidity: Table 6 – Turbidity Sampling Method Turbidity Meter/Turbidimeter (required for disturbances 5 acres or greater in size) X Transparency Tube (option for disturbances less than 1 acre and up to 5 acres in size) The benchmark for turbidity value is 25 nephelometric turbidity units (NTU) and a transparency less than 33 centimeters. If the discharge’s turbidity is 26 to 249 NTU or the transparency is less than 33 cm but equal to or greater than 6 cm, the following steps will be conducted: 1. Review the SWPPP for compliance with Special Condition S9. Make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period. 3. Document BMP implementation and maintenance in the site log book. If the turbidity exceeds 250 NTU or the transparency is 6 cm or less at any time, the following steps will be conducted: 1. Telephone or submit an electronic report to the applicable Ecology Region’s Environmental Report Tracking System (ERTS) within 24 hours. https://www.ecology.wa.gov/About-us/Get-involved/Report-an-environmental-issue • Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish, Whatcom): (425) 649-7000 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period 3. Document BMP implementation and maintenance in the site log book. 4. Continue to sample discharges daily until one of the following is true: • Turbidity is 25 NTU (or lower). • Transparency is 33 cm (or greater). • Compliance with the water quality limit for turbidity is achieved. o 1 - 5 NTU over background turbidity, if background is less than 50 NTU o 1% - 10% over background turbidity, if background is 50 NTU or greater • The discharge stops or is eliminated. pH Sampling (4.2.2) pH monitoring is required for “Significant concrete work” (i.e. greater than 1000 cubic yards poured concrete or recycled concrete over the life of the project).The use of engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD] or fly ash) also requires pH monitoring. For significant concrete work, pH sampling will start the first day concrete is poured and continue until it is cured, typically three (3) weeks after the last pour. For engineered soils and recycled concrete, pH sampling begins when engineered soils or recycled concrete are first exposed to precipitation and continues until the area is fully stabilized. If the measured pH is 8.5 or greater, the following measures will be taken: 1. Prevent high pH water from entering storm sewer systems or surface water. 2. Adjust or neutralize the high pH water to the range of 6.5 to 8.5 su using appropriate technology such as carbon dioxide (CO2) sparging (liquid or dry ice). 3. Written approval will be obtained from Ecology prior to the use of chemical treatment other than CO2 sparging or dry ice. Method for sampling pH: Table 7 – pH Sampling Method pH meter X pH test kit Wide range pH indicator paper Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies (5.0) 303(d) Listed Waterbodies (5.1) Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH? Yes No List the impairment(s): N/A The receiving waterbody, Springbrook Creek, is impaired for: Bioassessment. All stormwater and dewatering discharges from the site are subject to an effluent limit of 8.5 su for pH and/or 25 NTU for turbidity. TMDL Waterbodies (5.2) Waste Load Allocation for CWSGP discharges: No known waste load allocation for CWSGP discharges. The Construction Stormwater General Permit Proposed New Discharge to an Impaired Water Body form is included in Appendix F. Reporting and Record Keeping (6.0) Record Keeping (6.1) Site Log Book (6.1.1) A site log book will be maintained for all on-site construction activities and will include: • A record of the implementation of the SWPPP and other permit requirements • Site inspections • Sample logs Records Retention (6.1.2) Records will be retained during the life of the project and for a minimum of three (3) years following the termination of permit coverage in accordance with Special Condition S5.C of the CSWGP. Permit documentation to be retained on-site: • CSWGP • Permit Coverage Letter • SWPPP • Site Log Book Permit documentation will be provided within 14 days of receipt of a written request from Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP. Updating the SWPPP (6.1.3) The SWPPP will be modified if: • Found ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. • There is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. The SWPPP will be modified within seven (7) days if inspection(s) or investigation(s) determine additional or modified BMPs are necessary for compliance. An updated timeline for BMP implementation will be prepared. Reporting (6.2) Discharge Monitoring Reports (6.2.1) Cumulative soil disturbance is one (1) acre or larger; therefore, Discharge Monitoring Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given monitoring period the DMR will be submitted as required, reporting “No Discharge”. The DMR due date is fifteen (15) days following the end of each calendar month. DMRs will be reported online through Ecology’s WQWebDMR System. Notification of Noncompliance (6.2.2) If any of the terms and conditions of the permit is not met, and the resulting noncompliance may cause a threat to human health or the environment, the following actions will be taken: 1. Ecology will be notified within 24-hours of the failure to comply by calling the applicable Regional office ERTS phone number (Regional office numbers listed below). 2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or correct the noncompliance. If applicable, sampling and analysis of any noncompliance will be repeated immediately and the results submitted to Ecology within five (5) days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to Ecology within five (5) days, unless requested earlier by Ecology. Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6 cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as required by Special Condition S5.A of the CSWGP. • Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit, Snohomish, or Whatcom County Include the following information: 1. Your name and / Phone number 2. Permit number 3. City / County of project 4. Sample results 5. Date / Time of call 6. Date / Time of sample 7. Project name In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH water. Appendix/Glossary A. Site Map B. BMP Detail C. Site Inspection Form D. Construction Stormwater General Permit (CSWGP) E. Engineering Calculations Construction Stormwater Site Inspection Form Page 1 Project Name Sapphire on Talbot Permit # Inspection Date Time Name of Certified Erosion Sediment Control Lead (CESCL) or qualified inspector if less than one acre Print Name: Approximate rainfall amount since the last inspection (in inches): Approximate rainfall amount in the last 24 hours (in inches): Current Weather Clear Cloudy Mist Rain Wind Fog A. Type of inspection: Weekly Post Storm Event Other B. Phase of Active Construction (check all that apply): Pre Construction/installation of erosion/sediment controls Clearing/Demo/Grading Infrastructure/storm/roads Concrete pours Vertical Construction/buildings Utilities Offsite improvements Site temporary stabilized Final stabilization C. Questions: 1. Were all areas of construction and discharge points inspected? Yes No 2. Did you observe the presence of suspended sediment, turbidity, discoloration, or oil sheen Yes No 3. Was a water quality sample taken during inspection? (refer to permit conditions S4 & S5) Yes No 4. Was there a turbid discharge 250 NTU or greater, or Transparency 6 cm or less?* Yes No 5. If yes to #4 was it reported to Ecology? Yes No 6. Is pH sampling required? pH range required is 6.5 to 8.5. Yes No If answering yes to a discharge, describe the event. Include when, where, and why it happened; what action was taken, and when. *If answering yes to # 4 record NTU/Transparency with continual sampling daily until turbidity is 25 NTU or less/ transparency is 33 cm or greater. Sampling Results: Date: Parameter Method (circle one) Result Other/Note NTU cm pH Turbidity tube, meter, laboratory pH Paper, kit, meter Construction Stormwater Site Inspection Form Page 2 D. Check the observed status of all items. Provide “Action Required “details and dates. Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 1 Clearing Limits Before beginning land disturbing activities are all clearing limits, natural resource areas (streams, wetlands, buffers, trees) protected with barriers or similar BMPs? (high visibility recommended) 2 Construction Access Construction access is stabilized with quarry spalls or equivalent BMP to prevent sediment from being tracked onto roads? Sediment tracked onto the road way was cleaned thoroughly at the end of the day or more frequent as necessary. 3 Control Flow Rates Are flow control measures installed to control stormwater volumes and velocity during construction and do they protect downstream properties and waterways from erosion? If permanent infiltration ponds are used for flow control during construction, are they protected from siltation? 4 Sediment Controls All perimeter sediment controls (e.g. silt fence, wattles, compost socks, berms, etc.) installed, and maintained in accordance with the Stormwater Pollution Prevention Plan (SWPPP). Sediment control BMPs (sediment ponds, traps, filters etc.) have been constructed and functional as the first step of grading. Stormwater runoff from disturbed areas is directed to sediment removal BMP. 5 Stabilize Soils Have exposed un-worked soils been stabilized with effective BMP to prevent erosion and sediment deposition? Construction Stormwater Site Inspection Form Page 3 Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 5 Stabilize Soils Cont. Are stockpiles stabilized from erosion, protected with sediment trapping measures and located away from drain inlet, waterways, and drainage channels? Have soils been stabilized at the end of the shift, before a holiday or weekend if needed based on the weather forecast? 6 Protect Slopes Has stormwater and ground water been diverted away from slopes and disturbed areas with interceptor dikes, pipes and or swales? Is off-site storm water managed separately from stormwater generated on the site? Is excavated material placed on uphill side of trenches consistent with safety and space considerations? Have check dams been placed at regular intervals within constructed channels that are cut down a slope? 7 Drain Inlets Storm drain inlets made operable during construction are protected. Are existing storm drains within the influence of the project protected? 8 Stabilize Channel and Outlets Have all on-site conveyance channels been designed, constructed and stabilized to prevent erosion from expected peak flows? Is stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes and downstream conveyance systems? 9 Control Pollutants Are waste materials and demolition debris handled and disposed of to prevent contamination of stormwater? Has cover been provided for all chemicals, liquid products, petroleum products, and other material? Has secondary containment been provided capable of containing 110% of the volume? Were contaminated surfaces cleaned immediately after a spill incident? Were BMPs used to prevent contamination of stormwater by a pH modifying sources? Construction Stormwater Site Inspection Form Page 4 Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 9 Cont. Wheel wash wastewater is handled and disposed of properly. 10 Control Dewatering Concrete washout in designated areas. No washout or excess concrete on the ground. Dewatering has been done to an approved source and in compliance with the SWPPP. Were there any clean non turbid dewatering discharges? 11 Maintain BMP Are all temporary and permanent erosion and sediment control BMPs maintained to perform as intended? 12 Manage the Project Has the project been phased to the maximum degree practicable? Has regular inspection, monitoring and maintenance been performed as required by the permit? Has the SWPPP been updated, implemented and records maintained? 13 Protect LID Is all Bioretention and Rain Garden Facilities protected from sedimentation with appropriate BMPs? Is the Bioretention and Rain Garden protected against over compaction of construction equipment and foot traffic to retain its infiltration capabilities? Permeable pavements are clean and free of sediment and sediment laden- water runoff. Muddy construction equipment has not been on the base material or pavement. Have soiled permeable pavements been cleaned of sediments and pass infiltration test as required by stormwater manual methodology? Heavy equipment has been kept off existing soils under LID facilities to retain infiltration rate. E. Check all areas that have been inspected. All in place BMPs All disturbed soils All concrete wash out area All material storage areas All discharge locations All equipment storage areas All construction entrances/exits Construction Stormwater Site Inspection Form Page 5 F. Elements checked “Action Required” (section D) describe corrective action to be taken. List the element number; be specific on location and work needed. Document, initial, and date when the corrective action has been completed and inspected. Element # Description and Location Action Required Completion Date Initials Attach additional page if needed Sign the following certification: “I certify that this report is true, accurate, and complete, to the best of my knowledge and belief” Inspected by: (print) (Signature) Date: Title/Qualification of Inspector: Construction Stormwater General Permit Page 2 TABLE OF CONTENTS LIST OF TABLES ...........................................................................................................................3 SUMMARY OF PERMIT REPORT SUBMITTALS .....................................................................4 SPECIAL CONDITIONS ................................................................................................................5 S1.PERMIT COVERAGE ........................................................................................................5 S2. APPLICATION REQUIREMENTS ...................................................................................8 S3.COMPLIANCE WITH STANDARDS .............................................................................12 S4.MONITORING REQUIREMENTS, BENCHMARKS, AND REPORTING TRIGGERS ................................................................................................13 S5.REPORTING AND RECORDKEEPING REQUIREMENTS .........................................20 S6.PERMIT FEES...................................................................................................................23 S7.SOLID AND LIQUID WASTE DISPOSAL ....................................................................23 S8. DISCHARGES TO 303(d) OR TMDL WATERBODIES ................................................23 S9.STORMWATER POLLUTION PREVENTION PLAN...................................................27 S10. NOTICE OF TERMINATION .........................................................................................37 GENERAL CONDITIONS ...........................................................................................................38 G1. DISCHARGE VIOLATIONS ...........................................................................................38 G2.SIGNATORY REQUIREMENTS.....................................................................................38 G3.RIGHT OF INSPECTION AND ENTRY .........................................................................39 G4. GENERAL PERMIT MODIFICATION AND REVOCATION ......................................39 G5.REVOCATION OF COVERAGE UNDER THE PERMIT .............................................39 G6.REPORTING A CAUSE FOR MODIFICATION ............................................................40 G7.COMPLIANCE WITH OTHER LAWS AND STATUTES .............................................40 G8. DUTY TO REAPPLY .......................................................................................................40 G9. TRANSFER OF GENERAL PERMIT COVERAGE .......................................................41 G10.REMOVED SUBSTANCES .............................................................................................41 G11. DUTY TO PROVIDE INFORMATION ...........................................................................41 G12. OTHER REQUIREMENTS OF 40 CFR ...........................................................................41 G13. ADDITIONAL MONITORING ........................................................................................41 G14.PENALTIES FOR VIOLATING PERMIT CONDITIONS .............................................41 G15. UPSET ...............................................................................................................................42 G16.PROPERTY RIGHTS ........................................................................................................42 Construction Stormwater General Permit Page 3 G17. DUTY TO COMPLY ........................................................................................................42 G18. TOXIC POLLUTANTS.....................................................................................................42 G19.PENALTIES FOR TAMPERING .....................................................................................43 G20.REPORTING PLANNED CHANGES .............................................................................43 G21.REPORTING OTHER INFORMATION ..........................................................................43 G22.REPORTING ANTICIPATED NON-COMPLIANCE .....................................................43 G23.REQUESTS TO BE EXCLUDED FROM COVERAGE UNDER THE PERMIT ..........44 G24. APPEALS ..........................................................................................................................44 G25.SEVERABILITY ...............................................................................................................44 G26.BYPASS PROHIBITED ....................................................................................................44 APPENDIX A DEFINITIONS ...................................................................................................47 APPENDIX B ACRONYMS .....................................................................................................55 LIST OF TABLES Table 1: Summary of Required Submittals ................................................................................... 4 Table 2: Summary of Required On-site Documentation............................................................... 4 Table 3: Summary of Primary Monitoring Requirements .......................................................... 15 Table 4: Monitoring and Reporting Requirements ..................................................................... 17 Table 5:Turbidity, Fine Sediment & Phosphorus Sampling and Limits for 303(d)-Listed Waters .................................................................................................... 25 Table 6:pH Sampling and Limits for 303(d)-Listed Waters ...................................................... 26 Construction Stormwater General Permit Page 4 SUMMARY OF PERMIT REPORT SUBMITTALS Refer to the Special and General Conditions within this permit for additional submittal requirements. Appendix A provides a list of definitions. Appendix B provides a list of acronyms. Table 1: Summary of Required Submittals Permit Section Submittal Frequency First Submittal Date S5.A and S8 High Turbidity/Transparency Phone Reporting As Necessary Within 24 hours S5.B Discharge Monitoring Report Monthly* Within 15 days following the end of each month S5.F and S8 Noncompliance Notification Telephone Notification As necessary Within 24-hours S5.F Noncompliance Notification Written Report As necessary Within 5 Days of non- compliance S9.C Request for Chemical Treatment Form As necessary Written approval from Ecology is required prior to using chemical treatment (with the exception of dry ice or CO2 to adjust pH) G2 Notice of Change in Authorization As necessary G6 Permit Application for Substantive Changes to the Discharge As necessary G8 Application for Permit Renewal 1/permit cycle No later than 180 days before expiration G9 Notice of Permit Transfer As necessary G20 Notice of Planned Changes As necessary G22 Reporting Anticipated Non- compliance As necessary SPECIAL NOTE: *Permittees must submit electronic Discharge Monitoring Reports (DMRs) to the Washington State Department of Ecology monthly, regardless of site discharge, for the full duration of permit coverage. Refer to Section S5.B of this General Permit for more specific information regarding DMRs. Table 2: Summary of Required On-site Documentation Document Title Permit Conditions Permit Coverage Letter See Conditions S2, S5 Construction Stormwater General Permit See Conditions S2, S5 Site Log Book See Conditions S4, S5 Stormwater Pollution Prevention Plan (SWPPP) See Conditions S9, S5 Construction Stormwater General Permit Page 5 SPECIAL CONDITIONS S1. PERMIT COVERAGE A. Permit Area This Construction Stormwater General Permit (CSWGP) covers all areas of Washington State, except for federal operators and Indian Country as specified in Special Condition S1.E.3. B. Operators Required to Seek Coverage Under this General Permit: 1. Operators of the following construction activities are required to seek coverage under this CSWGP: a. Clearing, grading and/or excavation that results in the disturbance of one or more acres (including off-site disturbance acreage authorized in S1.C.2) and discharges stormwater to surface waters of the State; and clearing, grading and/or excavation on sites smaller than one acre that are part of a larger common plan of development or sale, if the common plan of development or sale will ultimately disturb one acre or more and discharge stormwater to surface waters of the State. i. This includes forest practices (including, but not limited to, class IV conversions) that are part of a construction activity that will result in the disturbance of one or more acres, and discharge to surface waters of the State (that is, forest practices that prepare a site for construction activities); and b. Any size construction activity discharging stormwater to waters of the State that the Washington State Department of Ecology (Ecology): i. Determines to be a significant contributor of pollutants to waters of the State of Washington. ii. Reasonably expects to cause a violation of any water quality standard. 2. Operators of the following activities are not required to seek coverage under this CSWGP (unless specifically required under Special Condition S1.B.1.b. above): a. Construction activities that discharge all stormwater and non-stormwater to ground water, sanitary sewer, or combined sewer, and have no point source discharge to either surface water or a storm sewer system that drains to surface waters of the State. b. Construction activities covered under an Erosivity Waiver (Special Condition S2.C). c. Routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility. Construction Stormwater General Permit Page 6 C. Authorized Discharges: 1. Stormwater Associated with Construction Activity. Subject to compliance with the terms and conditions of this permit, Permittees are authorized to discharge stormwater associated with construction activity to surface waters of the State or to a storm sewer system that drains to surface waters of the State. (Note that waters of the State example, a creek running through a site.) 2. Stormwater Associated with Construction Support Activity. This permit also authorizes stormwater discharge from support activities related to the permitted construction site (for example, an on-site portable rock crusher, off-site equipment staging yards, material storage areas, borrow areas, etc.) provided: a. The support activity relates directly to the permitted construction site that is required to have an NPDES permit; and b. The support activity is not a commercial operation serving multiple unrelated construction projects, and does not operate beyond the completion of the construction activity; and c. Appropriate controls and measures are identified in the Stormwater Pollution Prevention Plan (SWPPP) for the discharges from the support activity areas. 3. Non-Stormwater Discharges. The categories and sources of non-stormwater discharges identified below are authorized conditionally, provided the discharge is consistent with the terms and conditions of this permit: a. Discharges from fire-fighting activities. b. Fire hydrant system flushing. c. Potable water, including uncontaminated water line flushing. d. Hydrostatic test water. e. Uncontaminated air conditioning or compressor condensate. f. Uncontaminated ground water or spring water. g. Uncontaminated excavation dewatering water (in accordance with S9.D.10). h. Uncontaminated discharges from foundation or footing drains. i. Uncontaminated or potable water used to control dust. Permittees must minimize the amount of dust control water used. j. Routine external building wash down that does not use detergents. k. Landscape irrigation water. The SWPPP must adequately address all authorized non-stormwater discharges, except for discharges from fire-fighting activities, and must comply with Special Condition S3. Construction Stormwater General Permit Page 7 At a minimum, discharges from potable water (including water line flushing), fire hydrant system flushing, and pipeline hydrostatic test water must undergo the following: dechlorination to a concentration of 0.1 parts per million (ppm) or less, and pH adjustment to within 6.5 8.5 standard units (su), if necessary. D. Prohibited Discharges: The following discharges to waters of the State, including ground water, are prohibited. 1. Concrete wastewater. 2. Wastewater from washout and clean-up of stucco, paint, form release oils, curing compounds and other construction materials. 3. Process wastewater as defined by 40 Code of Federal Regulations (CFR) 122.2 (see Appendix A of this permit). 4. Slurry materials and waste from shaft drilling, including process wastewater from shaft drilling for construction of building, road, and bridge foundations unless managed according to Special Condition S9.D.9.j. 5. Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance. 6. Soaps or solvents used in vehicle and equipment washing. 7. Wheel wash wastewater, unless managed according to Special Condition S9.D.9. 8. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, unless managed according to Special Condition S9.D.10. E. Limits on Coverage Ecology may require any discharger to apply for and obtain coverage under an individual permit or another more specific general permit. Such alternative coverage will be required when Ecology determines that this CSWGP does not provide adequate assurance that water quality will be protected, or there is a reasonable potential for the project to cause or contribute to a violation of water quality standards. The following stormwater discharges are not covered by this permit: 1. Post-construction stormwater discharges that originate from the site after completion of construction activities and the site has undergone final stabilization. 2. Non-point source silvicultural activities such as nursery operations, site preparation, reforestation and subsequent cultural treatment, thinning, prescribed burning, pest and fire control, harvesting operations, surface drainage, or road construction and maintenance, from which there is natural runoff as excluded in 40 CFR Subpart 122. 3. Stormwater from any federal operator. Construction Stormwater General Permit Page 8 4. Stormwater from f U.S.C.§1151, except portions of the Puyallup Reservation as noted below. Indian Country includes: a. All land within any Indian Reservation notwithstanding the issuance of any patent, and, including rights-of-way running through the reservation. This includes all federal, tribal, and Indian and non-Indian privately owned land within the reservation. b. All off-reservation Indian allotments, the Indian titles to which have not been extinguished, including rights-of-way running through the same. c. All off-reservation federal trust lands held for Native American Tribes. Puyallup Exception: Following the Puyallup Tribes of Indians Land Settlement Act of 1989, 25 U.S.C. §1773; the permit does apply to land within the Puyallup Reservation except for discharges to surface water on land held in trust by the federal government. 5. Stormwater from any site covered under an existing NPDES individual permit in which stormwater management and/or treatment requirements are included for all stormwater discharges associated with construction activity. 6. Stormwater from a site where an applicable Total Maximum Daily Load (TMDL) requirement specifically precludes or prohibits discharges from construction activity. S2. APPLICATION REQUIREMENTS A. Permit Application Forms 1. Notice of Intent Form/Timeline a. Operators of new or previously unpermitted construction activities must submit a complete and accurate permit application (Notice of Intent, or NOI) to Ecology. b. Operators must apply using the electronic application form (NOI) available on http://www.ecy.wa.gov/programs/wq/stormwater/ construction/index.html. Permittees unable to submit electronically (for example, those who do not have an internet connection) must contact Ecology to request a waiver and obtain instructions on how to obtain a paper NOI. Department of Ecology Water Quality Program - Construction Stormwater PO Box 47696 Olympia, Washington 98504-7696 Construction Stormwater General Permit Page 9 c. The operator must submit the NOI at least 60 days before discharging stormwater from construction activities and must submit it on or before the date of the first public notice (see Special Condition S2.B below for details). The 30- day public comment period begins on the publication date of the second public notice. Unless Ecology responds to the complete application in writing, based on public comments, or any other relevant factors, coverage under the general permit will automatically commence on the thirty-first day following receipt by Ecology of a completed NOI, or the issuance date of this permit, whichever is later; unless Ecology specifies a later date in writing as required by WAC173- 226-200(2). d. If an applicant intends to use a Best Management Practice (BMP) selected on the basis of Special applicant must notify Ecology of its selection as part of the NOI. In the event the applicant selects BMPs after submission of the NOI, it must provide notice of the selection of an equivalent BMP to Ecology at least 60 days before intended use of the equivalent BMP. e. Permittees must notify Ecology regarding any changes to the information provided on the NOI by submitting an updated NOI. Examples of such changes include, but are not limited to: i. Changes to the Permittee s mailing address, ii. Changes to the on-site contact person information, and iii. Changes to the area/acreage affected by construction activity. f. Applicants must notify Ecology if they are aware of contaminated soils and/or groundwater associated with the construction activity. Provide detailed information with the NOI (as known and readily available) on the nature and extent of the contamination (concentrations, locations, and depth), as well as pollution prevention and/or treatment BMPs proposed to control the discharge of soil and/or groundwater contaminants in stormwater. Examples of such detail may include, but are not limited to: i. List or table of all known contaminants with laboratory test results showing concentration and depth, ii. Map with sample locations, iii. Temporary Erosion and Sediment Control (TESC) plans, iv. Related portions of the Stormwater Pollution Prevention Plan (SWPPP) that address the management of contaminated and potentially contaminated construction stormwater and dewatering water, v. Dewatering plan and/or dewatering contingency plan. Construction Stormwater General Permit Page 10 2. Transfer of Coverage Form The Permittee can transfer current coverage under this permit to one or more new operators, including operators of sites within a Common Plan of Development, provided the Permittee submits a Transfer of Coverage Form in accordance with General Condition G9. Transfers do not require public notice. B. Public Notice For new or previously unpermitted construction activities, the applicant must publish a public notice at least one time each week for two consecutive weeks, at least 7 days apart, in a newspaper with general circulation in the county where the construction is to take place. The notice must contain: 1. he applicant is seeking coverage under the Washington State Discharge General Permit . 2. The name, address and location of the construction site. 3. The name and address of the applicant. 4. The type of construction activity that will result in a discharge (for example, residential construction, commercial construction, etc.), and the number of acres to be disturbed. 5. The name of the receiving water(s) (that is, the surface water(s) to which the site will discharge), or, if the discharge is through a storm sewer system, the name of the operator of the system. 6. The statement: Any persons desiring to present their views to the Washington State Department of Ecology regarding this application, or interested in Ecology action on this application, may notify Ecology in writing no later than 30 days of the last date of publication of this notice. Ecology reviews public comments and considers whether discharges from this project would cause a measurable change in receiving water quality, and, if so, whether the project is necessary and in the overriding public interest according to Tier II antidegradation requirements under WAC 173-201A-320. Comments can be submitted to: Department of Ecology, PO Box 47696, Olympia, Washington 98504-7696 Attn: Water Quality Program, Construction Stormwater. Construction Stormwater General Permit Page 11 C. Erosivity Waiver Construction site operators may qualify for an erosivity waiver from the CSWGP if the following conditions are met: 1. The site will result in the disturbance of fewer than 5 acres and the site is not a portion of a common plan of development or sale that will disturb 5 acres or greater. 2. a. period of construction activity, as calculated (see the CSWGP homepage http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html for a link to the EPA s calculator Factor in the EPA Erosivity Waiver Fact Sheet). The period of construction activity starts when the land is first disturbed and ends with final stabilization. In addition: b. The entire period of construction activity must fall within the following timeframes: i. For sites west of the Cascades Crest: June 15 September 15. ii. For sites east of the Cascades Crest, excluding the Central Basin: June 15 October 15. iii. For sites east of the Cascades Crest, within the Central Basin: no additional timeframe restrictions apply. The Central Basin is defined as the portions of Eastern Washington with mean annual precipitation of less than 12 inches. For a map of the Central Basin (Average Annual Precipitation Region 2), refer to http://www.ecy.wa.gov/programs/wq/stormwater/ construction/resourcesguidance.html. 3. Construction site operators must submit a complete Erosivity Waiver certification form at least one week before disturbing the land. Certification must include statements that the operator will: a. Comply with applicable local stormwater requirements; and b. Implement appropriate erosion and sediment control BMPs to prevent violations of water quality standards. 4. This waiver is not available for facilities declared significant contributors of pollutants as defined in Special Condition S1.B.1.b. or for any size construction activity that could reasonably expect to cause a violation of any water quality standard as defined in Special Condition S1.B.1.b.ii. 5. This waiver does not apply to construction activities which include non- stormwater discharges listed in Special Condition S1.C.3. Construction Stormwater General Permit Page 12 6. If construction activity extends beyond the certified waiver period for any reason, the operator must either: a. and the entire project falls within the applicable regional timeframe in Special Condition S2.C.2.b, complete and submit an amended waiver certification form before the original waiver expires; or b. Submit a complete permit application to Ecology in accordance with Special Condition S2.A and B before the end of the certified waiver period. S3. COMPLIANCE WITH STANDARDS A. Discharges must not cause or contribute to a violation of surface water quality standards (Chapter 173-201A WAC), ground water quality standards (Chapter 173-200 WAC), sediment management standards (Chapter 173-204 WAC), and human health-based criteria in the National Toxics Rule (40 CFR Part 131.36). Discharges not in compliance with these standards are not authorized. B. Prior to the discharge of stormwater and non-stormwater to waters of the State, the Permittee must apply all known, available, and reasonable methods of prevention, control, and treatment (AKART). This includes the preparation and implementation of an adequate SWPPP, with all appropriate BMPs installed and maintained in accordance with the SWPPP and the terms and conditions of this permit. C. Ecology presumes that a Permittee complies with water quality standards unless discharge monitoring data or other site-specific information demonstrates that a discharge causes or contributes to a violation of water quality standards, when the Permittee complies with the following conditions. The Permittee must fully: 1. Comply with all permit conditions, including planning, sampling, monitoring, reporting, and recordkeeping conditions. 2. Implement stormwater BMPs contained in stormwater management manuals published or approved by Ecology, or BMPs that are demonstrably equivalent to BMPs contained in stormwater technical manuals published or approved by Ecology, including the proper selection, implementation, and maintenance of all applicable and appropriate BMPs for on-site pollution control. (For purposes of this section, the stormwater manuals listed in Appendix 10 of the Phase I Municipal Stormwater Permit are approved by Ecology.) D. Where construction sites also discharge to ground water, the ground water discharges must also meet the terms and conditions of this CSWGP. Permittees who discharge to ground water through an injection well must also comply with any applicable requirements of the Underground Injection Control (UIC) regulations, Chapter 173-218 WAC. Construction Stormwater General Permit Page 13 S4. MONITORING REQUIREMENTS, BENCHMARKS AND REPORTING TRIGGERS A. Site Log Book The Permittee must maintain a site log book that contains a record of the implementation of the SWPPP and other permit requirements, including the installation and maintenance of BMPs, site inspections, and stormwater monitoring. B. Site Inspections activities, all BMPs, and all stormwater discharge points under the Permittee s operational control. (See Special Conditions S4.B.3 and B.4 below for detailed [CESCL].) Construction sites one acre or larger that discharge stormwater to surface waters of the State must have site inspections conducted by a certified CESCL. Sites less than one acre may have a person without CESCL certification conduct inspections. 1. The Permittee must examine stormwater visually for the presence of suspended sediment, turbidity, discoloration, and oil sheen. The Permittee must evaluate the effectiveness of BMPs and determine if it is necessary to install, maintain, or repair BMPs to improve the quality of stormwater discharges. Based on the results of the inspection, the Permittee must correct the problems identified by: a. Reviewing the SWPPP for compliance with Special Condition S9 and making appropriate revisions within 7 days of the inspection. b. Immediately beginning the process of fully implementing and maintaining appropriate source control and/or treatment BMPs as soon as possible, addressing the problems no later than within 10 days of the inspection. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when an extension is requested by a Permittee within the initial 10-day response period. c. Documenting BMP implementation and maintenance in the site log book. 2. The Permittee must inspect all areas disturbed by construction activities, all BMPs, and all stormwater discharge points at least once every calendar week and within 24 hours of any discharge from the site. (For purposes of this condition, individual discharge events that last more than one day do not require daily inspections. For example, if a stormwater pond discharges continuously over the course of a week, only one inspection is required that week.) The Permittee may reduce the inspection frequency for temporarily stabilized, inactive sites to once every calendar month. Construction Stormwater General Permit Page 14 3. The Permittee must have staff knowledgeable in the principles and practices of erosion and sediment control. The CESCL (sites one acre or more) or inspector (sites less than one acre) must have the skills to assess the: a. Site conditions and construction activities that could impact the quality of stormwater, and b. Effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. 4. The SWPPP must identify the CESCL or inspector, who must be present on site or on-call at all times. The CESCL must obtain this certification through an approved erosion and sediment control training program that meets the minimum training standards established by Ecology (see BMP C160 in the manual referred to in Special Condition S9.C.1 and 2). 5. The Permittee must summarize the results of each inspection in an inspection report or checklist and enter the report/checklist into, or attach it to, the site log book. At a minimum, each inspection report or checklist must include: a. Inspection date and time. b. Weather information, the general conditions during inspection and the approximate amount of precipitation since the last inspection, and precipitation within the last 24 hours. c. A summary or list of all implemented BMPs, including observations of all erosion/sediment control structures or practices. d. A description of the locations: i. Of BMPs inspected; ii. Of BMPs that need maintenance and why; iii. Of BMPs that failed to operate as designed or intended; and iv. Where additional or different BMPs are needed, and why. e. A description of stormwater discharged from the site. The Permittee must note the presence of suspended sediment, turbidity, discoloration, and oil sheen, as applicable. f. Any water quality monitoring performed during inspection. g. General comments and notes, including a brief description of any BMP repairs, maintenance or installations made following the inspection. h. A summary report and a schedule of implementation of the remedial actions that the Permittee plans to take if the site inspection indicates that the site is out of compliance. The remedial actions taken must meet the requirements of the SWPPP and the permit. Construction Stormwater General Permit Page 15 i. The name, title, and signature of the person conducting the site inspection, a phone number or other reliable method to reach this person, and the following Table 3: Summary of Primary Monitoring Requirements Size of Soil Disturbance1 Weekly Site Inspections Weekly Sampling w/ Turbidity Meter Weekly Sampling w/ Transparency Tube Weekly pH Sampling2 CESCL Required for Inspections? Sites that disturb less than 1 acre, but are part of a larger Common Plan of Development Required Not Required Not Required Not Required No Sites that disturb 1 acre or more, but fewer than 5 acres Required Sampling Required either method3 Required Yes Sites that disturb 5 acres or more Required Required Not Required4 Required Yes 1 Soil disturbance is calculated by adding together all areas that will be affected by construction activity. Construction activity means clearing, grading, excavation, and any other activity that disturbs the surface of the land, including ingress/egress from the site. 2 If construction activity results in the disturbance of 1 acre or more, and involves significant concrete work (1,000 cubic yards of poured concrete or recycled concrete over the life of a project) or the use of engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD], or fly ash), and stormwater from the affected area drains to surface waters of the State or to a storm sewer stormwater collection system that drains to other surface waters of the State, the Permittee must conduct pH sampling in accordance with Special Condition S4.D. 3 Sites with one or more acres, but fewer than 5 acres of soil disturbance, must conduct turbidity or transparency sampling in accordance with Special Condition S4.C. 4 Sites equal to or greater than 5 acres of soil disturbance must conduct turbidity sampling using a turbidity meter in accordance with Special Condition S4.C. Construction Stormwater General Permit Page 16 C. Turbidity/Transparency Sampling Requirements 1. Sampling Methods a. If construction activity involves the disturbance of 5 acres or more, the Permittee must conduct turbidity sampling per Special Condition S4.C. b. If construction activity involves 1 acre or more but fewer than 5 acres of soil disturbance, the Permittee must conduct either transparency sampling or turbidity sampling per Special Condition S4.C. 2. Sampling Frequency a. The Permittee must sample all discharge points at least once every calendar week when stormwater (or authorized non-stormwater) discharges from the site or enters any on-site surface waters of the state (for example, a creek running through a site); sampling is not required on sites that disturb less than an acre. b. Samples must be representative of the flow and characteristics of the discharge. c. Sampling is not required when there is no discharge during a calendar week. d. Sampling is not required outside of normal working hours or during unsafe conditions. e. If the Permittee is unable to sample during a monitoring period, the Permittee must include a brief explanation in the monthly Discharge Monitoring Report (DMR). f. Sampling is not required before construction activity begins. g. The Permittee may reduce the sampling frequency for temporarily stabilized, inactive sites to once every calendar month. 3. Sampling Locations a. Sampling is required at all points where stormwater associated with construction activity (or authorized non-stormwater) is discharged off site, including where it enters any on-site surface waters of the state (for example, a creek running through a site). b. The Permittee may discontinue sampling at discharge points that drain areas of the project that are fully stabilized to prevent erosion. c. The Permittee must identify all sampling point(s) on the SWPPP site map and clearly mark these points in the field with a flag, tape, stake or other visible marker. d. Sampling is not required for discharge that is sent directly to sanitary or combined sewer systems. Construction Stormwater General Permit Page 17 e. The Permittee may discontinue sampling at discharge points in areas of the project where the Permittee no longer has operational control of the construction activity. 4. Sampling and Analysis Methods a. The Permittee performs turbidity analysis with a calibrated turbidity meter (turbidimeter) either on site or at an accredited lab. The Permittee must record the results in the site log book in nephelometric turbidity units (NTUs). b. The Permittee performs transparency analysis on site with a 1¾-inch-diameter, 60-centimeter (cm)-long transparency tube. The Permittee will record the results in the site log book in centimeters (cm). Table 4: Monitoring and Reporting Requirements Parameter Unit Analytical Method Sampling Frequency Benchmark Value Phone Reporting Trigger Value Turbidity NTU SM2130 Weekly, if discharging 25 NTUs 250 NTUs Transparency cm Manufacturer instructions, or Ecology guidance Weekly, if discharging 33 cm 6 cm 5. Turbidity/Transparency Benchmark Values and Reporting Triggers The benchmark value for turbidity is 25 NTUs or less. The benchmark value for transparency is 33 centimeters (cm). Note: Benchmark values do not apply to discharges to segments of water (Category 5) for turbidity, fine sediment, or phosphorus; these discharges are subject to a numeric effluent limit for turbidity. Refer to Special Condition S8 for more information. a. Turbidity 26 249 NTUs, or Transparency 32 7 cm: If the discharge turbidity is 26 to 249 NTUs; or if discharge transparency is less than 33 cm, but equal to or greater than 6 cm, the Permittee must: i. Review the SWPPP for compliance with Special Condition S9 and make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. ii. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, addressing the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period. Construction Stormwater General Permit Page 18 iii. Document BMP implementation and maintenance in the site log book. b. Turbidity 250 NTUs or greater, or Transparency 6 cm or less: NTUs or greater, or if discharge transparency is less than or equal to 6 cm, the Permittee must complete the reporting and adaptive management process described below. i. Telephone or submit an electronic report to the applicable Ecology (or Permit Submittals when the form is available) within 24 hours, in accordance with Special Condition S5.A. Central Region (Okanogan, Chelan, Douglas, Kittitas, Yakima, Klickitat, Benton): (509) 575-2490 Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400 Northwest Region (Kitsap, Snohomish, Island, King, San Juan, Skagit, Whatcom): (425) 649-7000 Southwest Region (Grays Harbor, Lewis, Mason, Thurston, Pierce, Clark, Cowlitz, Skamania, Wahkiakum, Clallam, Jefferson, Pacific): (360) 407-6300 Links to these numbers and the ERTS reporting page are located on the following web site: http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html. ii. Review the SWPPP for compliance with Special Condition S9 and make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. iii. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, addressing the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period. iv. Document BMP implementation and maintenance in the site log book. v. Sample discharges daily until: a) Turbidity is 25 NTUs (or lower); or b) Transparency is 33 cm (or greater); or Construction Stormwater General Permit Page 19 c) The Permittee has demonstrated compliance with the water quality limit for turbidity: 1) No more than 5 NTUs over background turbidity, if background is less than 50 NTUs, or 2) No more than 10% over background turbidity, if background is 50 NTUs or greater; or d) The discharge stops or is eliminated. D. pH Sampling Requirements Significant Concrete Work or Engineered Soils If construction activity results in the disturbance of 1 acre or more, and involves significant concrete work (significant concrete work means greater than 1000 cubic yards poured concrete or recycled concrete used over the life of a project) or the use of engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD], or fly ash), and stormwater from the affected area drains to surface waters of the State or to a storm sewer system that drains to surface waters of the State, the Permittee must conduct pH sampling as set forth below. Note: In addition, discharges to segments of water (Category 5) for high pH are subject to a numeric effluent limit for pH; refer to Special Condition S8. 1. For sites with significant concrete work, the Permittee must begin the pH sampling period when the concrete is first poured and exposed to precipitation, and continue weekly throughout and after the concrete pour and curing period, until stormwater pH is in the range of 6.5 to 8.5 (su). 2. For sites with recycled concrete where monitoring is required, the Permittee must begin the weekly pH sampling period when the recycled concrete is first exposed to precipitation and must continue until the recycled concrete is fully stabilized with the stormwater pH in the range of 6.5 to 8.5 (su). 3. For sites with engineered soils, the Permittee must begin the pH sampling period when the soil amendments are first exposed to precipitation and must continue until the area of engineered soils is fully stabilized. 4. During the applicable pH monitoring period defined above, the Permittee must obtain a representative sample of stormwater and conduct pH analysis at least once per week. 5. The Permittee must sample pH in the sediment trap/pond(s) or other locations that receive stormwater runoff from the area of significant concrete work or engineered soils before the stormwater discharges to surface waters. 6. The benchmark value for pH is 8.5 standard units. Anytime sampling indicates that pH is 8.5 or greater, the Permittee must either: Construction Stormwater General Permit Page 20 a. Prevent the high pH water (8.5 or above) from entering storm sewer systems or surface waters; or b. If necessary, adjust or neutralize the high pH water until it is in the range of pH 6.5 to 8.5 (su) using an appropriate treatment BMP such as carbon dioxide (CO2) sparging or dry ice. The Permittee must obtain written approval from Ecology before using any form of chemical treatment other than CO2 sparging or dry ice. 7. The Permittee must perform pH analysis on site with a calibrated pH meter, pH test kit, or wide range pH indicator paper. The Permittee must record pH sampling results in the site log book. S5. REPORTING AND RECORDKEEPING REQUIREMENTS A. High Turbidity Reporting Anytime sampling performed in accordance with Special Condition S4.C indicates turbidity has reached the 250 NTUs or more (or transparency less than or equal to 6 cm) high turbidity reporting level, the Permittee must either call the applicable Ecology Region by phone within 24 hours of analysis or submit an electronic ERTS report (or submit an electronic report Permit Submittals when the form is available). See the CSWGP web site for links to ERTS and the WQWebPortal: http://www.ecy.wa.gov/programs/wq/stormwater/construction/ index.html. Also, see phone numbers in Special Condition S4.C.5.b.i. B. Discharge Monitoring Reports (DMRs) Permittees required to conduct water quality sampling in accordance with Special Conditions S4.C (Turbidity/Transparency), S4.D (pH), S8 (303[d]/TMDL sampling), and/or G13 (Additional Sampling) must submit the results to Ecology. Permittees must submit monitoring data using Ecology's WQWebDMR web application . To find out more information and to sign up for WQWebDMR go to: http://www.ecy.wa.gov/programs/ wq/permits/paris/portal.html. Permittees unable to submit electronically (for example, those who do not have an internet connection) must contact Ecology to request a waiver and obtain instructions on how to obtain a paper copy DMR at: Department of Ecology Water Quality Program - Construction Stormwater PO Box 47696 Olympia, Washington 98504-7696 Permittees who obtain a waiver not to use WQWebDMR must use the forms provided to them by Ecology; submittals must be mailed to the address above. Permittees shall Construction Stormwater General Permit Page 21 submit DMR forms to be received by Ecology within 15 days following the end of each month. If there was no discharge during a given monitoring period, all Permittees must submit a DMR . DMRs are required for the full duration of permit coverage (from issuance date to termination). For more information, contact Ecology staff using information provided at the following web site: www.ecy.wa.gov/programs/wq/permits/paris/contacts.html. C. Records Retention The Permittee must retain records of all monitoring information (site log book, sampling results, inspection reports/checklists, etc.), Stormwater Pollution Prevention Plan, copy of the permit coverage letter (including Transfer of Coverage documentation), and any other documentation of compliance with permit requirements for the entire life of the construction project and for a minimum of three years following the termination of permit coverage. Such information must include all calibration and maintenance records, and records of all data used to complete the application for this permit. This period of retention must be extended during the course of any unresolved litigation regarding the discharge of pollutants by the Permittee or when requested by Ecology. D. Recording Results For each measurement or sample taken, the Permittee must record the following information: 1. Date, place, method, and time of sampling or measurement. 2. The first and last name of the individual who performed the sampling or measurement. 3. The date(s) the analyses were performed. 4. The first and last name of the individual who performed the analyses. 5. The analytical techniques or methods used. 6. The results of all analyses. E. Additional Monitoring by the Permittee If the Permittee monitors any pollutant more frequently than required by this permit using test procedures specified by Special Condition S4 of this permit, the results of this monitoring must be included in the calculation and reporting of the data submitted in the . F. Noncompliance Notification In the event the Permittee is unable to comply with any part of the terms and conditions of this permit, and the resulting noncompliance may cause a threat to human health or the environment (such as but not limited to spills of fuels or other materials, catastrophic pond or slope failure, and discharges that violate water quality standards), or exceed Construction Stormwater General Permit Page 22 numeric effluent limitations (see S8. Discharges to 303(d) or TMDL Waterbodies), the Permittee must, upon becoming aware of the circumstance: 1. Notify Ecology within 24-hours of the failure to comply by calling the applicable Regional office ERTS phone number (refer to Special Condition S4.C.5.b.i. or www.ecy.wa.gov/programs/wq/stormwater/construction/turbidity.html for Regional ERTS phone numbers). 2. Immediately take action to prevent the discharge/pollution, or otherwise stop or correct the noncompliance, and, if applicable, repeat sampling and analysis of any noncompliance immediately and submit the results to Ecology within five (5) days of becoming aware of the violation. 3. Submit a detailed written report to Ecology within five (5) days, of the time the Permittee becomes aware of the circumstances, unless requested earlier by Ecology. The report must be submitted using Portal (WQWebPortal) - Permit Submittals, unless a waiver from electronic reporting has been granted according to S5.B. The report must contain a description of the noncompliance, including exact dates and times, and if the noncompliance has not been corrected, the anticipated time it is expected to continue; and the steps taken or planned to reduce, eliminate, and prevent reoccurrence of the noncompliance. The Permittee must report any unanticipated bypass and/or upset that exceeds any effluent limit in the permit in accordance with the 24-hour reporting requirement contained in 40 C.F.R. 122.41(l)(6). Compliance with these requirements does not relieve the Permittee from responsibility to maintain continuous compliance with the terms and conditions of this permit or the resulting liability for failure to comply. Upon request of the Permittee, Ecology may waive the requirement for a written report on a case-by- case basis, if the immediate notification is received by Ecology within 24 hours. G. Access to Plans and Records 1. The Permittee must retain the following permit documentation (plans and records) on site, or within reasonable access to the site, for use by the operator or for on-site review by Ecology or the local jurisdiction: a. General Permit b. Permit Coverage Letter c. Stormwater Pollution Prevention Plan (SWPPP) d. Site Log Book 2. The Permittee must address written requests for plans and records listed above (Special Condition S5.G.1) as follows: Construction Stormwater General Permit Page 23 a. The Permittee must provide a copy of plans and records to Ecology within 14 days of receipt of a written request from Ecology. b. The Permittee must provide a copy of plans and records to the public when requested in writing. Upon receiving a written request from the public for the i. Provide a copy of the plans and records to the requester within 14 days of a receipt of the written request; or ii. Notify the requester within 10 days of receipt of the written request of the location and times within normal business hours when the plans and records may be viewed; and provide access to the plans and records within 14 days of receipt of the written request; or iii. Within 14 days of receipt of the written request, the Permittee may submit a copy of the plans and records to Ecology for viewing and/or copying by the requester at an Ecology office, or a mutually agreed location. If plans and records are viewed and/or copied at a location other than at an Ecology office, the Permittee will provide reasonable access to copying services for which a reasonable fee may be charged. The Permittee must notify the requester within 10 days of receipt of the request where the plans and records may be viewed and/or copied. S6. PERMIT FEES The Permittee must pay permit fees assessed by Ecology. Fees for stormwater discharges covered under this permit are established by Chapter 173-224 WAC. Ecology continues to assess permit fees until the permit is terminated in accordance with Special Condition S10 or revoked in accordance with General Condition G5. S7. SOLID AND LIQUID WASTE DISPOSAL The Permittee must handle and dispose of solid and liquid wastes generated by construction activity, such as demolition debris, construction materials, contaminated materials, and waste materials from maintenance activities, including liquids and solids from cleaning catch basins and other stormwater facilities, in accordance with: A. Special Condition S3, Compliance with Standards B. WAC 173-216-110 C. Other applicable regulations S8. DISCHARGES TO 303(d) OR TMDL WATERBODIES A. Sampling and Numeric Effluent Limits For Certain Discharges to 303(d)-listed Waterbodies Construction Stormwater General Permit Page 24 1. Permittees who discharge to segments of waterbodies listed as impaired by the State of Washington under Section 303(d) of the Clean Water Act for turbidity, fine sediment, high pH, or phosphorus, must conduct water quality sampling according to the requirements of this section, and Special Conditions S4.C.2.b-f and S4.C.3.b-d, and must comply with the applicable numeric effluent limitations in S8.C and S8.D. 2. All references and requirements associated with Section 303(d) of the Clean Water Act mean the most current listing by Ecology of impaired waters (Category 5) that exists on January 1, 2016 application is received by Ecology, whichever is later. B. Limits on Coverage for New Discharges to TMDL or 303(d)-listed Waters Operators of construction sites that discharge to a TMDL or 303(d)-listed waterbody are not eligible for coverage under this permit unless the operator: 1. Prevents exposing stormwater to pollutants for which the waterbody is impaired, and retains documentation in the SWPPP that details procedures taken to prevent exposure on site; or 2. Documents that the pollutants for which the waterbody is impaired are not present at the site, and retains documentation of this finding within the SWPPP; or 3. Provides Ecology with data indicating the discharge is not expected to cause or contribute to an exceedance of a water quality standard, and retains such data on site with the SWPPP. The operator must provide data and other technical information to Ecology that sufficiently demonstrate: a. For discharges to waters without an EPA-approved or -established TMDL, that the discharge of the pollutant for which the water is impaired will meet in- stream water quality criteria at the point of discharge to the waterbody; or b. For discharges to waters with an EPA-approved or -established TMDL, that there is sufficient remaining wasteload allocation in the TMDL to allow construction stormwater discharge and that existing dischargers to the waterbody are subject to compliance schedules designed to bring the waterbody into attainment with water quality standards. Operators of construction sites are eligible for coverage under this permit if Ecology issues permit coverage based upon an affirmative determination that the discharge will not cause or contribute to the existing impairment. C. Sampling and Numeric Effluent Limits for Discharges to Water Bodies on the 303(d) List for Turbidity, Fine Sediment, or Phosphorus 1. Permittees who discharge to segments of water bodies on the 303(d) list (Category 5) for turbidity, fine sediment, or phosphorus must conduct turbidity sampling in accordance with Special Condition S4.C.2 and comply with either of the numeric effluent limits noted in Table 5 below. Construction Stormwater General Permit Page 25 2. As an alternative to the 25 NTUs effluent limit noted in Table 5 below (applied at the point where stormwater [or authorized non-stormwater] is discharged off-site), Permittees may choose to comply with the surface water quality standard for turbidity. The standard is: no more than 5 NTUs over background turbidity when the background turbidity is 50 NTUs or less, or no more than a 10% increase in turbidity when the background turbidity is more than 50 NTUs. In order to use the water quality standard requirement, the sampling must take place at the following locations: a. Background turbidity in the 303(d)-listed receiving water immediately upstream (upgradient) or outside the area of influence of the discharge. b. Turbidity at the point of discharge into the 303(d)-listed receiving water, inside the area of influence of the discharge. 3. Discharges that exceed the numeric effluent limit for turbidity constitute a violation of this permit. 4. Permittees whose discharges exceed the numeric effluent limit shall sample discharges daily until the violation is corrected and comply with the non- compliance notification requirements in Special Condition S5.F. Table 5: Turbidity, Fine Sediment & Phosphorus Sampling and Limits for 303(d)-Listed Waters Parameter identified in 303(d) listing Parameter Sampled Unit Analytical Method Sampling Frequency Numeric Effluent Limit1 Turbidity Fine Sediment Phosphorus Turbidity NTU SM2130 Weekly, if discharging 25 NTUs, at the point where stormwater is discharged from the site; OR In compliance with the surface water quality standard for turbidity (S8.C.2.a) 1Permittees subject to a numeric effluent limit for turbidity may, at their discretion, choose either numeric effluent limitation based on site-specific considerations including, but not limited to, safety, access and convenience. D. Discharges to Water Bodies on the 303(d) List for High pH 1. Permittees who discharge to segments of water bodies on the 303(d) list (Category 5) for high pH must conduct pH sampling in accordance with the table below, and comply with the numeric effluent limit of pH 6.5 to 8.5 su (Table 6). Construction Stormwater General Permit Page 26 Table 6: pH Sampling and Limits for 303(d)-Listed Waters Parameter identified in 303(d) listing Parameter Sampled/Units Analytical Method Sampling Frequency Numeric Effluent Limit High pH pH /Standard Units pH meter Weekly, if discharging In the range of 6.5 8.5 2. At the Permittee s discretion, compliance with the limit shall be assessed at one of the following locations: a. Directly in the 303(d)-listed waterbody segment, inside the immediate area of influence of the discharge; or b. Alternatively, the Permittee may measure pH at the point where the discharge leaves the construction site, rather than in the receiving water. 3. Discharges that exceed the numeric effluent limit for pH (outside the range of 6.5 8.5 su) constitute a violation of this permit. 4. Permittees whose discharges exceed the numeric effluent limit shall sample discharges daily until the violation is corrected and comply with the non- compliance notification requirements in Special Condition S5.F. E. Sampling and Limits for Sites Discharging to Waters Covered by a TMDL or Another Pollution Control Plan 1. Discharges to a waterbody that is subject to a Total Maximum Daily Load (TMDL) for turbidity, fine sediment, high pH, or phosphorus must be consistent with the TMDL. Refer to http://www.ecy.wa.gov/programs/wq/tmdl/ TMDLsbyWria/TMDLbyWria.html for more information on TMDLs. a. Where an applicable TMDL sets specific waste load allocations or requirements for discharges covered by this permit, discharges must be consistent with any specific waste load allocations or requirements established by the applicable TMDL. i. The Permittee must sample discharges weekly or as otherwise specified by the TMDL to evaluate compliance with the specific waste load allocations or requirements. ii. Analytical methods used to meet the monitoring requirements must conform to the latest revision of the Guidelines Establishing Test Procedures for the Analysis of Pollutants contained in 40 CFR Part 136. Turbidity and pH methods need not be accredited or registered unless conducted at a laboratory which must otherwise be accredited or registered. b. Where an applicable TMDL has established a general waste load allocation for construction stormwater discharges, but has not identified specific requirements, Construction Stormwater General Permit Page 27 compliance with Special Conditions S4 (Monitoring) and S9 (SWPPPs) will constitute compliance with the approved TMDL. c. Where an applicable TMDL has not specified a waste load allocation for construction stormwater discharges, but has not excluded these discharges, compliance with Special Conditions S4 (Monitoring) and S9 (SWPPPs) will constitute compliance with the approved TMDL. d. Where an applicable TMDL specifically precludes or prohibits discharges from construction activity, the operator is not eligible for coverage under this permit. 2. Applicable TMDL means a TMDL for turbidity, fine sediment, high pH, or phosphorus that is completed and approved by EPA before January 1, 2016, or permit application is received by Ecology, whichever is later. application is received by Ecology become applicable to the Permittee only if they are imposed through an administrative order by Ecology, or through a modification of permit coverage. S9. STORMWATER POLLUTION PREVENTION PLAN The Permittee must prepare and properly implement an adequate Stormwater Pollution Prevention Plan (SWPPP) for construction activity in accordance with the requirements of this permit beginning with initial soil disturbance and until final stabilization. A. 1. To implement best management practices (BMPs) to prevent erosion and sedimentation, and to identify, reduce, eliminate or prevent stormwater contamination and water pollution from construction activity. 2. To prevent violations of surface water quality, ground water quality, or sediment management standards. 3. To control peak volumetric flow rates and velocities of stormwater discharges. B. General Requirements 1. The SWPPP must include a narrative and drawings. All BMPs must be clearly referenced in the narrative and marked on the drawings. The SWPPP narrative must include documentation to explain and justify the pollution prevention decisions made for the project. Documentation must include: a. Information about existing site conditions (topography, drainage, soils, vegetation, etc.). b. Potential erosion problem areas. c. The 13 elements of a SWPPP in Special Condition S9.D.1-13, including BMPs used to address each element. Construction Stormwater General Permit Page 28 d. Construction phasing/sequence and general BMP implementation schedule. e. The actions to be taken if BMP performance goals are not achieved for example, a contingency plan for additional treatment and/or storage of stormwater that would violate the water quality standards if discharged. f. Engineering calculations for ponds, treatment systems, and any other designed structures. When a treatment system requires engineering calculations, these calculations must be included in the SWPPP. Engineering calculations do not need to be included in the SWPPP for treatment systems that do not require such calculations. 2. The Permittee must modify the SWPPP if, during inspections or investigations conducted by the owner/operator, or the applicable local or state regulatory authority, it is determined that the SWPPP is, or would be, ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. The Permittee must then: a. Review the SWPPP for compliance with Special Condition S9 and make appropriate revisions within 7 days of the inspection or investigation. b. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, addressing the problems no later than 10 days from the inspection or investigation. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when an extension is requested by a Permittee within the initial 10-day response period. c. Document BMP implementation and maintenance in the site log book. The Permittee must modify the SWPPP whenever there is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. C. Stormwater Best Management Practices (BMPs) BMPs must be consistent with: 1. Stormwater Management Manual for Western Washington (most current approved edition at the time this permit was issued), for sites west of the crest of the Cascade Mountains; or 2. Stormwater Management Manual for Eastern Washington (most current approved edition at the time this permit was issued), for sites east of the crest of the Cascade Mountains; or 3. Revisions to the manuals listed in Special Condition S9.C.1. & 2., or other stormwater management guidance documents or manuals which provide an equivalent level of pollution prevention, that are approved by Ecology and incorporated into this permit in accordance with the permit modification requirements of WAC 173-226-230; or Construction Stormwater General Permit Page 29 4. Documentation in the SWPPP that the BMPs selected provide an equivalent level of pollution prevention, compared to the applicable Stormwater Management Manuals, including: a. The technical basis for the selection of all stormwater BMPs (scientific, technical studies, and/or modeling) that support the performance claims for the BMPs being selected. b. An assessment of how the selected BMP will satisfy AKART requirements and the applicable federal technology-based treatment requirements under 40 CFR part 125.3. D. SWPPP Narrative Contents and Requirements The Permittee must include each of the 13 elements below in Special Condition S9.D.1-13 in the narrative of the SWPPP and implement them unless site conditions render the element unnecessary and the exemption from that element is clearly justified in the SWPPP. 1. Preserve Vegetation/Mark Clearing Limits a. Before beginning land-disturbing activities, including clearing and grading, clearly mark all clearing limits, sensitive areas and their buffers, and trees that are to be preserved within the construction area. b. Retain the duff layer, native topsoil, and natural vegetation in an undisturbed state to the maximum degree practicable. 2. Establish Construction Access a. Limit construction vehicle access and exit to one route, if possible. b. Stabilize access points with a pad of quarry spalls, crushed rock, or other equivalent BMPs, to minimize tracking sediment onto roads. c. Locate wheel wash or tire baths on site, if the stabilized construction entrance is not effective in preventing tracking sediment onto roads. d. If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day, or more frequently as necessary (for example, during wet weather). Remove sediment from roads by shoveling, sweeping, or pickup and transport of the sediment to a controlled sediment disposal area. e. Conduct street washing only after sediment removal in accordance with Special Condition S9.D.2.d. Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tributary to waters of the State. 3. Control Flow Rates a. Protect properties and waterways downstream of development sites from erosion and the associated discharge of turbid waters due to increases in the Construction Stormwater General Permit Page 30 velocity and peak volumetric flow rate of stormwater runoff from the project site, as required by local plan approval authority. b. Where necessary to comply with Special Condition S9.D.3.a, construct stormwater retention or detention facilities as one of the first steps in grading. Assure that detention facilities function properly before constructing site improvements (for example, impervious surfaces). c. If permanent infiltration ponds are used for flow control during construction, protect these facilities from siltation during the construction phase. 4. Install Sediment Controls The Permittee must design, install and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. At a minimum, the Permittee must design, install and maintain such controls to: a. Construct sediment control BMPs (sediment ponds, traps, filters, infiltration facilities, etc.) as one of the first steps in grading. These BMPs must be functional before other land disturbing activities take place. b. Minimize sediment discharges from the site. The design, installation and maintenance of erosion and sediment controls must address factors such as the amount, frequency, intensity and duration of precipitation, the nature of resulting stormwater runoff, and soil characteristics, including the range of soil particle sizes expected to be present on the site. c. Direct stormwater runoff from disturbed areas through a sediment pond or other appropriate sediment removal BMP, before the runoff leaves a construction site or before discharge to an infiltration facility. Runoff from fully stabilized areas may be discharged without a sediment removal BMP, but must meet the flow control performance standard of Special Condition S9.D.3.a. d. Locate BMPs intended to trap sediment on site in a manner to avoid interference with the movement of juvenile salmonids attempting to enter off-channel areas or drainages. e. Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal and maximize stormwater infiltration, unless infeasible. f. Where feasible, design outlet structures that withdraw impounded stormwater from the surface to avoid discharging sediment that is still suspended lower in the water column. 5. Stabilize Soils a. The Permittee must stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. Applicable BMPs include, but are not limited to: temporary and permanent seeding, sodding, mulching, plastic covering, erosion control fabrics and matting, soil application of polyacrylamide Construction Stormwater General Permit Page 31 (PAM), the early application of gravel base on areas to be paved, and dust control. b. The Permittee must control stormwater volume and velocity within the site to minimize soil erosion. c. The Permittee must control stormwater discharges, including both peak flow rates and total stormwater volume, to minimize erosion at outlets and to minimize downstream channel and stream bank erosion. d. Depending on the geographic location of the project, the Permittee must not allow soils to remain exposed and unworked for more than the time periods set forth below to prevent erosion: *Note: The Central Basin is defined as the portions of Eastern Washington with mean annual precipitation of less than 12 inches. e. The Permittee must stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather forecast. f. The Permittee must stabilize soil stockpiles from erosion, protected with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. g. The Permittee must minimize the amount of soil exposed during construction activity. h. The Permittee must minimize the disturbance of steep slopes. i. The Permittee must minimize soil compaction and, unless infeasible, preserve topsoil. 6. Protect Slopes a. The Permittee must design and construct cut-and-fill slopes in a manner to minimize erosion. Applicable practices include, but are not limited to, reducing continuous length of slope with terracing and diversions, reducing slope steepness, and roughening slope surfaces (for example, track walking). Construction Stormwater General Permit Page 32 b. The Permittee must divert off-site stormwater (run-on) or ground water away from slopes and disturbed areas with interceptor dikes, pipes, and/or swales. Off-site stormwater should be managed separately from stormwater generated on the site. c. At the top of slopes, collect drainage in pipe slope drains or protected channels to prevent erosion. i. West of the Cascade Mountains Crest: Temporary pipe slope drains must handle the peak 10-minute flow rate from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour flow rate predicted by an approved continuous runoff model, increased by a factor of 1.6, may be used. The hydrologic analysis must use the existing land cover condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis must use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. If using the Western Washington Hydrology Model (WWHM) to predict flows, bare ii. East of the Cascade Mountains Crest: Temporary pipe slope drains must handle the expected peak flow rate from a 6-month, 3-hour storm for the developed condition, referred to as the short duration storm. d. Place excavated material on the uphill side of trenches, consistent with safety and space considerations. e. Place check dams at regular intervals within constructed channels that are cut down a slope. 7. Protect Drain Inlets a. Protect all storm drain inlets made operable during construction so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. b. Clean or remove and replace inlet protection devices when sediment has filled one-third of the available storage (unless a different standard is specified by the product manufacturer). 8. Stabilize Channels and Outlets a. Design, construct and stabilize all on-site conveyance channels to prevent erosion from the following expected peak flows: i. West of the Cascade Mountains Crest: Channels must handle the peak 10-minute flow rate from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour flow rate indicated by an approved continuous runoff model, increased by a factor of 1.6, may be used. The hydrologic analysis must use the existing land Construction Stormwater General Permit Page 33 cover condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis must use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. If using the WWHM to predict flows, bare ii. East of the Cascade Mountains Crest: Channels must handle the expected peak flow rate from a 6-month, 3-hour storm for the developed condition, referred to as the short duration storm. b. Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes, and downstream reaches at the outlets of all conveyance systems. 9. Control Pollutants Design, install, implement and maintain effective pollution prevention measures to minimize the discharge of pollutants. The Permittee must: a. Handle and dispose of all pollutants, including waste materials and demolition debris that occur on site in a manner that does not cause contamination of stormwater. b. Provide cover, containment, and protection from vandalism for all chemicals, liquid products, petroleum products, and other materials that have the potential to pose a threat to human health or the environment. On-site fueling tanks must include secondary containment. Secondary containment means placing tanks or containers within an impervious structure capable of containing 110% of the volume contained in the largest tank within the containment structure. Double- walled tanks do not require additional secondary containment. c. Conduct maintenance, fueling, and repair of heavy equipment and vehicles using spill prevention and control measures. Clean contaminated surfaces immediately following any spill incident. d. Discharge wheel wash or tire bath wastewater to a separate on-site treatment system that prevents discharge to surface water, such as closed-loop recirculation or upland land application, or to the sanitary sewer with local sewer district approval. e. Apply fertilizers and pesticides in a manner and at application rates that will not result in loss of chemical to stormwater runoff. requirements for application rates and procedures. f. Use BMPs to prevent contamination of stormwater runoff by pH-modifying sources. The sources for this contamination include, but are not limited to: bulk cement, cement kiln dust, fly ash, new concrete washing and curing waters, recycled concrete stockpiles, waste streams generated from concrete grinding and sawing, exposed aggregate processes, dewatering concrete vaults, concrete Construction Stormwater General Permit Page 34 pumping and mixer washout waters. (Also refer to the definition for "concrete wastewater" in Appendix A--Definitions.) g. Adjust the pH of stormwater or authorized non-stormwater if necessary to prevent an exceedance of groundwater and/or surface water quality standards. h. Assure that washout of concrete trucks is performed off-site or in designated concrete washout areas only. Do not wash out concrete truck drums or concrete handling equipment onto the ground, or into storm drains, open ditches, streets, or streams. Washout of concrete handling equipment may be disposed of in a designated concrete washout area or in a formed area awating concrete where it will not contaminate surface or ground water. Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage or concrete discharge directly to groundwater or surface waters of the State is prohibited. Do not wash out to formed areas awaiting LID facilities. i. Obtain written approval from Ecology before using any chemical treatment, with the exception of CO2 or dry ice used to adjust pH. j. Uncontaminated water from water-only based shaft drilling for construction of building, road, and bridge foundations may be infiltrated provided the wastewater is managed in a way that prohibits discharge to surface waters. Prior to infiltration, water from water-only based shaft drilling that comes into contact with curing concrete must be neutralized until pH is in the range of 6.5 to 8.5 (su). 10. Control Dewatering a. Permittees must discharge foundation, vault, and trench dewatering water, which have characteristics similar to stormwater runoff at the site, into a controlled conveyance system before discharge to a sediment trap or sediment pond. b. Permittees may discharge clean, non-turbid dewatering water, such as well- point ground water, to systems tributary to, or directly into surface waters of the State, as specified in Special Condition S9.D.8, provided the dewatering flow does not cause erosion or flooding of receiving waters. Do not route clean dewatering water through stormwater sediment ponds. of the S creek running through a site. c. Other dewatering treatment or disposal options may include: i. Infiltration. ii. Transport off site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner that does not pollute state waters. Construction Stormwater General Permit Page 35 iii. Ecology-approved on-site chemical treatment or other suitable treatment technologies (see S9.D.9.i. regarding chemical treatment written approval). iv. Sanitary or combined sewer discharge with local sewer district approval, if there is no other option. v. Use of a sedimentation bag with discharge to a ditch or swale for small volumes of localized dewatering. d. Permittees must handle highly turbid or contaminated dewatering water separately from stormwater. 11. Maintain BMPs a. Permittees must maintain and repair all temporary and permanent erosion and sediment control BMPs as needed to assure continued performance of their intended function in accordance with BMP specifications. b. Permittees must remove all temporary erosion and sediment control BMPs within 30 days after achieving final site stabilization or after the temporary BMPs are no longer needed. 12. Manage the Project a. Phase development projects to the maximum degree practicable and take into account seasonal work limitations. b. Inspection and monitoring Inspect, maintain and repair all BMPs as needed to assure continued performance of their intended function. Conduct site inspections and monitoring in accordance with Special Condition S4. c. Maintaining an updated construction SWPPP Maintain, update, and implement the SWPPP in accordance with Special Conditions S3, S4 and S9. 13. Protect Low Impact Development (LID) BMPs The primary purpose of LID BMPs/On-site LID Stormwater Management BMPs is to reduce the disruption of the natural site hydrology. LID BMPs are permanent facilities. a. Permittees must protect all Bioretention and Rain Garden facilities from sedimentation through installation and maintenance of erosion and sediment control BMPs on portions of the site that drain into the Bioretention and/or Rain Garden facilities. Restore the facilities to their fully functioning condition if they accumulate sediment during construction. Restoring the facility must include removal of sediment and any sediment-laden Bioretention/Rain Garden soils, and replacing the removed soils with soils meeting the design specification. Construction Stormwater General Permit Page 36 b. Permittees must maintain the infiltration capabilities of Bioretention and Rain Garden facilities by protecting against compaction by construction equipment and foot traffic. Protect completed lawn and landscaped areas from compaction due to construction equipment. c. Permittees must control erosion and avoid introducing sediment from surrounding land uses onto permeable pavements. Do not allow muddy construction equipment on the base material or pavement. Do not allow sediment-laden runoff onto permeable pavements. d. Permittees must clean permeable pavements fouled with sediments or no longer passing an initial infiltration test using local stormwater manual methodology or e. Permittees must keep all heavy equipment off existing soils under LID facilities that have been excavated to final grade to retain the infiltration rate of the soils. E. SWPPP Map Contents and Requirements example, a USGS quadrangle map, a portion of a county or city map, or other appropriate map) with enough detail to identify the location of the construction site and receiving waters within one mile of the site. The SWPPP must also include a legible site map (or maps) showing the entire construction site. The following features must be identified, unless not applicable due to site conditions: 1. The direction of north, property lines, and existing structures and roads. 2. Cut and fill slopes indicating the top and bottom of slope catch lines. 3. Approximate slopes, contours, and direction of stormwater flow before and after major grading activities. 4. Areas of soil disturbance and areas that will not be disturbed. 5. Locations of structural and nonstructural controls (BMPs) identified in the SWPPP. 6. Locations of off-site material, stockpiles, waste storage, borrow areas, and vehicle/equipment storage areas. 7. Locations of all surface water bodies, including wetlands. 8. Locations where stormwater or non-stormwater discharges off-site and/or to a surface waterbody, including wetlands. 9. Location of water quality sampling station(s), if sampling is required by state or local permitting authority. Construction Stormwater General Permit Page 37 10. Areas where final stabilization has been accomplished and no further construction- phase permit requirements apply. 11. Location or proposed location of LID facilities. S10. NOTICE OF TERMINATION A. The site is eligible for termination of coverage when it has met any of the following conditions: 1. The site has undergone final stabilization, the Permittee has removed all temporary BMPs (except biodegradable BMPs clearly manufactured with the intention for the material to be left in place and not interfere with maintenance or land use), and all stormwater discharges associated with construction activity have been eliminated; or 2. All portions of the site that have not undergone final stabilization per Special Condition S10.A.1 have been sold and/or transferred (per General Condition G9), and the Permittee no longer has operational control of the construction activity; or 3. For residential construction only, the Permittee has completed temporary stabilization and the homeowners have taken possession of the residences. B. When the site is eligible for termination, the Permittee must submit a complete and accurate Notice of Termination (NOT) form, signed in accordance with General Condition G2, to: Department of Ecology Water Quality Program Construction Stormwater PO Box 47696 Olympia, Washington 98504-7696 When an electronic termination form is available, the Permittee may choose to submit a complete and accurate Notice of Termination (NOT) form through the Water Quality Permitting Portal rather than mailing a hardcopy as noted above. The termination is effective on the thirty-first calendar day following the date Ecology receives a complete NOT form, unless Ecology notifies the Permittee that the termination request is denied because the Permittee has not met the eligibility requirements in Special Condition S10.A. Permittees are required to comply with all conditions and effluent limitations in the permit until the permit has been terminated. Permittees transferring the property to a new property owner or operator/Permittee are required to complete and submit the Notice of Transfer form to Ecology, but are not required to submit a Notice of Termination form for this type of transaction. Construction Stormwater General Permit Page 38 GENERAL CONDITIONS G1. DISCHARGE VIOLATIONS All discharges and activities authorized by this general permit must be consistent with the terms and conditions of this general permit. Any discharge of any pollutant more frequent than or at a level in excess of that identified and authorized by the general permit must constitute a violation of the terms and conditions of this permit. G2. SIGNATORY REQUIREMENTS A. All permit applications must bear a certification of correctness to be signed: 1. In the case of corporations, by a responsible corporate officer; 2. In the case of a partnership, by a general partner of a partnership; 3. In the case of sole proprietorship, by the proprietor; or 4. In the case of a municipal, state, or other public facility, by either a principal executive officer or ranking elected official. B. All reports required by this permit and other information requested by Ecology (including NOIs, NOTs, and Transfer of Coverage forms) must be signed by a person described above or by a duly authorized representative of that person. A person is a duly authorized representative only if: 1. The authorization is made in writing by a person described above and submitted to Ecology. 2. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility, such as the position of plant manager, superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters. C. Changes to authorization. If an authorization under paragraph G2.B.2 above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of paragraph G2.B.2 above must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by an authorized representative. D. Certification. Any person signing a document under this section must make the following certification: were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering information, the information submitted is, to the best of my Construction Stormwater General Permit Page 39 knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the G3. RIGHT OF INSPECTION AND ENTRY The Permittee must allow an authorized representative of Ecology, upon the presentation of credentials and such other documents as may be required by law: A. To enter upon the premises where a discharge is located or where any records are kept under the terms and conditions of this permit. B. To have access to and copy at reasonable times and at reasonable cost any records required to be kept under the terms and conditions of this permit. C. To inspect at reasonable times any facilities, equipment (including monitoring and control equipment), practices, methods, or operations regulated or required under this permit. D. To sample or monitor at reasonable times any substances or parameters at any location for purposes of assuring permit compliance or as otherwise authorized by the Clean Water Act. G4. GENERAL PERMIT MODIFICATION AND REVOCATION This permit may be modified, revoked and reissued, or terminated in accordance with the provisions of Chapter 173-226 WAC. Grounds for modification, revocation and reissuance, or termination include, but are not limited to, the following: A. When a change occurs in the technology or practices for control or abatement of pollutants applicable to the category of dischargers covered under this permit. B. When effluent limitation guidelines or standards are promulgated pursuant to the CWA or Chapter 90.48 RCW, for the category of dischargers covered under this permit. C. When a water quality management plan containing requirements applicable to the category of dischargers covered under this permit is approved, or D. When information is obtained that indicates cumulative effects on the environment from dischargers covered under this permit are unacceptable. G5. REVOCATION OF COVERAGE UNDER THE PERMIT Pursuant to Chapter 43.21B RCW and Chapter 173-226 WAC, the Director may terminate coverage for any discharger under this permit for cause. Cases where coverage may be terminated include, but are not limited to, the following: A. Violation of any term or condition of this permit. B. Obtaining coverage under this permit by misrepresentation or failure to disclose fully all relevant facts. Construction Stormwater General Permit Page 40 C. A change in any condition that requires either a temporary or permanent reduction or elimination of the permitted discharge. D. Failure or refusal of the Permittee to allow entry as required in RCW 90.48.090. E. A determination that the permitted activity endangers human health or the environment, or contributes to water quality standards violations. F. Nonpayment of permit fees or penalties assessed pursuant to RCW 90.48.465 and Chapter 173-224 WAC. G. Failure of the Permittee to satisfy the public notice requirements of WAC 173-226- 130(5), when applicable. The Director may require any discharger under this permit to apply for and obtain coverage under an individual permit or another more specific general permit. Permittees who have their coverage revoked for cause according to WAC 173-226-240 may request temporary coverage under this permit during the time an individual permit is being developed, provided the request is made within ninety (90) days from the time of revocation and is submitted along with a complete individual permit application form. G6. REPORTING A CAUSE FOR MODIFICATION The Permittee must submit a new application, or a supplement to the previous application, whenever a material change to the construction activity or in the quantity or type of discharge is anticipated which is not specifically authorized by this permit. This application must be submitted at least sixty (60) days prior to any proposed changes. Filing a request for a permit modification, revocation and reissuance, or termination, or a notification of planned changes or anticipated noncompliance does not relieve the Permittee of the duty to comply with the existing permit until it is modified or reissued. G7. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in this permit will be construed as excusing the Permittee from compliance with any applicable federal, state, or local statutes, ordinances, or regulations. G8. DUTY TO REAPPLY The Permittee must apply for permit renewal at least 180 days prior to the specified expiration date of this permit. The Permittee must reapply using the electronic application . Permittees unable to submit electronically (for example, those who do not have an internet connection) must contact Ecology to request a waiver and obtain instructions on how to obtain a paper NOI. Department of Ecology Water Quality Program - Construction Stormwater PO Box 47696 Olympia, Washington 98504-7696 Construction Stormwater General Permit Page 41 G9. TRANSFER OF GENERAL PERMIT COVERAGE Coverage under this general permit is automatically transferred to a new discharger, including operators of lots/parcels within a common plan of development or sale, if: A. A written agreement (Transfer of Coverage Form) between the current discharger (Permittee) and new discharger, signed by both parties and containing a specific date for transfer of permit responsibility, coverage, and liability (including any Administrative Orders associated with the Permit) is submitted to the Director; and B. intent to revoke coverage under the general permit. If this notice is not given, the transfer is effective on the date specified in the written agreement. When a current discharger (Permittee) transfers a portion of a permitted site, the current discharger must also submit an updated application form (NOI) to the Director indicating the remaining permitted acreage after the transfer. G10. REMOVED SUBSTANCES The Permittee must not re-suspend or reintroduce collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in the course of treatment or control of stormwater to the final effluent stream for discharge to state waters. G11. DUTY TO PROVIDE INFORMATION The Permittee must submit to Ecology, within a reasonable time, all information that Ecology may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit or to determine compliance with this permit. The Permittee must also submit to Ecology, upon request, copies of records required to be kept by this permit [40 CFR 122.41(h)]. G12. OTHER REQUIREMENTS OF 40 CFR All other requirements of 40 CFR 122.41 and 122.42 are incorporated in this permit by reference. G13. ADDITIONAL MONITORING Ecology may establish specific monitoring requirements in addition to those contained in this permit by administrative order or permit modification. G14. PENALTIES FOR VIOLATING PERMIT CONDITIONS Any person who is found guilty of willfully violating the terms and conditions of this permit shall be deemed guilty of a crime, and upon conviction thereof shall be punished by a fine of up to ten thousand dollars ($10,000) and costs of prosecution, or by imprisonment at the discretion of the court. Each day upon which a willful violation occurs may be deemed a separate and additional violation. Construction Stormwater General Permit Page 42 Any person who violates the terms and conditions of a waste discharge permit shall incur, in addition to any other penalty as provided by law, a civil penalty in the amount of up to ten thousand dollars ($10,000) for every such violation. Each and every such violation shall be a separate shall be deemed to be a separate and distinct violation. G15. UPSET Definition temporary noncompliance with technology-based permit effluent limitations because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. An upset constitutes an affirmative defense to an action brought for noncompliance with such technology-based permit effluent limitations if the requirements of the following paragraph are met. A Permittee who wishes to establish the affirmative defense of upset must demonstrate, through properly signed, contemporaneous operating logs or other relevant evidence that: 1) an upset occurred and that the Permittee can identify the cause(s) of the upset; 2) the permitted facility was being properly operated at the time of the upset; 3) the Permittee submitted notice of the upset as required in Special Condition S5.F, and; 4) the Permittee complied with any remedial measures required under this permit. In any enforcement proceeding, the Permittee seeking to establish the occurrence of an upset has the burden of proof. G16. PROPERTY RIGHTS This permit does not convey any property rights of any sort, or any exclusive privilege. G17. DUTY TO COMPLY The Permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or denial of a permit renewal application. G18. TOXIC POLLUTANTS The Permittee must comply with effluent standards or prohibitions established under Section 307(a) of the Clean Water Act for toxic pollutants within the time provided in the regulations that establish those standards or prohibitions, even if this permit has not yet been modified to incorporate the requirement. Construction Stormwater General Permit Page 43 G19. PENALTIES FOR TAMPERING The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders inaccurate any monitoring device or method required to be maintained under this permit shall, upon conviction, be punished by a fine of not more than $10,000 per violation, or by imprisonment for not more than two years per violation, or by both. If a conviction of a person is for a violation committed after a first conviction of such person under this condition, punishment shall be a fine of not more than $20,000 per day of violation, or imprisonment of not more than four (4) years, or both. G20. REPORTING PLANNED CHANGES The Permittee must, as soon as possible, give notice to Ecology of planned physical alterations, modifications or additions to the permitted construction activity. The Permittee should be aware that, depending on the nature and size of the changes to the original permit, a new public notice and other permit process requirements may be required. Changes in activities that require reporting to Ecology include those that will result in: A. The permitted facility being determined to be a new source pursuant to 40 CFR 122.29(b). B. A significant change in the nature or an increase in quantity of pollutants discharged, including but not limited to: for sites 5 acres or larger, a 20% or greater increase in acreage disturbed by construction activity. C. A change in or addition of surface water(s) receiving stormwater or non-stormwater from the construction activity. D. requirements in Special Condition S4. Following such notice, permit coverage may be modified, or revoked and reissued pursuant to 40 CFR 122.62(a) to specify and limit any pollutants not previously limited. Until such modification is effective, any new or increased discharge in excess of permit limits or not specifically authorized by this permit constitutes a violation. G21. REPORTING OTHER INFORMATION Where the Permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application or in any report to Ecology, it must promptly submit such facts or information. G22. REPORTING ANTICIPATED NON-COMPLIANCE The Permittee must give advance notice to Ecology by submission of a new application or supplement thereto at least forty-five (45) days prior to commencement of such discharges, of any facility expansions, production increases, or other planned changes, such as process modifications, in the permitted facility or activity which may result in noncompliance with permit limits or conditions. Any maintenance of facilities, which might necessitate Construction Stormwater General Permit Page 44 unavoidable interruption of operation and degradation of effluent quality, must be scheduled during non-critical water quality periods and carried out in a manner approved by Ecology. G23. REQUESTS TO BE EXCLUDED FROM COVERAGE UNDER THE PERMIT Any discharger authorized by this permit may request to be excluded from coverage under the general permit by applying for an individual permit. The discharger must submit to the Director an application as described in WAC 173-220-040 or WAC 173-216-070, whichever is applicable, with reasons supporting the request. These reasons will fully document how an individual permit will apply to the applicant in a way that the general permit cannot. Ecology may make specific requests for information to support the request. The Director will either issue an individual permit or deny the request with a statement explaining the reason for the denial. When an individual permit is issued to a discharger otherwise subject to the construction stormwater general permit, the applicability of the construction stormwater general permit to that Permittee is automatically terminated on the effective date of the individual permit. G24. APPEALS A. The terms and conditions of this general permit, as they apply to the appropriate class of dischargers, are subject to appeal by any person within 30 days of issuance of this general permit, in accordance with Chapter 43.21B RCW, and Chapter 173-226 WAC. B. The terms and conditions of this general permit, as they apply to an individual discharger, are appealable in accordance with Chapter 43.21B RCW within 30 days of the effective date of coverage of that discharger. Consideration of an appeal of general permit coverage of an individ applicability or nonapplicability to that individual discharger. C. The appeal of general permit coverage of an individual discharger does not affect any other dischargers covered under this general permit. If the terms and conditions of this general permit are found to be inapplicable to any individual discharger(s), the matter shall be remanded to Ecology for consideration of issuance of an individual permit or permits. G25. SEVERABILITY The provisions of this permit are severable, and if any provision of this permit, or application of any provision of this permit to any circumstance, is held invalid, the application of such provision to other circumstances, and the remainder of this permit shall not be affected thereby. G26. BYPASS PROHIBITED A. Bypass Procedures Bypass, which is the intentional diversion of waste streams from any portion of a treatment facility, is prohibited for stormwater events below the design criteria for Construction Stormwater General Permit Page 45 stormwater management. Ecology may take enforcement action against a Permittee for bypass unless one of the following circumstances (1, 2, 3 or 4) is applicable. 1. Bypass of stormwater is consistent with the design criteria and part of an approved management practice in the applicable stormwater management manual. 2. Bypass for essential maintenance without the potential to cause violation of permit limits or conditions. Bypass is authorized if it is for essential maintenance and does not have the potential to cause violations of limitations or other conditions of this permit, or adversely impact public health. 3. Bypass of stormwater is unavoidable, unanticipated, and results in noncompliance of this permit. This bypass is permitted only if: a. Bypass is unavoidable to prevent loss of life, personal injury, or severe property damage. property, damage to the treatment facilities which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. b. There are no feasible alternatives to the bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, maintenance during normal periods of equipment downtime (but not if adequate backup equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass which occurred during normal periods of equipment downtime or preventative maintenance), or transport of untreated wastes to another treatment facility. c. Ecology is properly notified of the bypass as required in Special Condition S5.F of this permit. 4. A planned action that would cause bypass of stormwater and has the potential to result in noncompliance of this permit during a storm event. The Permittee must notify Ecology at least thirty (30) days before the planned date of bypass. The notice must contain: a. A description of the bypass and its cause. b. An analysis of all known alternatives which would eliminate, reduce, or mitigate the need for bypassing. c. A cost-effectiveness analysis of alternatives including comparative resource damage assessment. d. The minimum and maximum duration of bypass under each alternative. e. A recommendation as to the preferred alternative for conducting the bypass. Construction Stormwater General Permit Page 46 f. The projected date of bypass initiation. g. A statement of compliance with SEPA. h. A request for modification of water quality standards as provided for in WAC 173-201A-110, if an exceedance of any water quality standard is anticipated. i. Steps taken or planned to reduce, eliminate, and prevent reoccurrence of the bypass. 5. For probable construction bypasses, the need to bypass is to be identified as early in the planning process as possible. The analysis required above must be considered during preparation of the Stormwater Pollution Prevention Plan (SWPPP) and must be included to the extent practical. In cases where the probable need to bypass is determined early, continued analysis is necessary up to and including the construction period in an effort to minimize or eliminate the bypass. Ecology will consider the following before issuing an administrative order for this type bypass: a. If the bypass is necessary to perform construction or maintenance-related activities essential to meet the requirements of this permit. b. If there are feasible alternatives to bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, stopping production, maintenance during normal periods of equipment down time, or transport of untreated wastes to another treatment facility. c. If the bypass is planned and scheduled to minimize adverse effects on the public and the environment. After consideration of the above and the adverse effects of the proposed bypass and any other relevant factors, Ecology will approve, conditionally approve, or deny the request. The public must be notified and given an opportunity to comment on bypass incidents of significant duration, to the extent feasible. Approval of a request to bypass will be by administrative order issued by Ecology under RCW 90.48.120. B. Duty to Mitigate The Permittee is required to take all reasonable steps to minimize or prevent any discharge or sludge use or disposal in violation of this permit that has a reasonable likelihood of adversely affecting human health or the environment. Construction Stormwater General Permit Page 47 APPENDIX A DEFINITIONS AKART is an acronym for all known, available, and reasonable methods of prevention, control, and treatment. AKART represents the most current methodology that can be reasonably required for preventing, controlling, or abating the pollutants and controlling pollution associated with a discharge. Applicable TMDL means a TMDL for turbidity, fine sediment, high pH, or phosphorus, which was completed and approved by EPA before January 1, 2016, or before the date the operator s complete permit application is received by Ecology, whichever is later. Applicant means an operator seeking coverage under this permit. Benchmark means a pollutant concentration used as a permit threshold, below which a pollutant is considered unlikely to cause a water quality violation, and above which it may. When pollutant concentrations exceed benchmarks, corrective action requirements take effect. Benchmark values are not water quality standards and are not numeric effluent limitations; they are indicator values. Best Management Practices (BMPs) means schedules of activities, prohibitions of practices, maintenance procedures, and other physical, structural and/or managerial practices to prevent or reduce the pollution of waters of the State. BMPs include treatment systems, operating procedures, and practices to control: stormwater associated with construction activity, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. Buffer means an area designated by a local jurisdiction that is contiguous to and intended to protect a sensitive area. Bypass means the intentional diversion of waste streams from any portion of a treatment facility. Calendar Day A period of 24 consecutive hours starting at 12:00 midnight and ending the following 12:00 midnight. Calendar Week (same as Week) means a period of seven consecutive days starting at 12:01 a.m. (0:01 hours) on Sunday. Certified Erosion and Sediment Control Lead (CESCL) means a person who has current certification through an approved erosion and sediment control training program that meets the minimum training standards established by Ecology (see BMP C160 in the SWMM). Chemical Treatment means the addition of chemicals to stormwater and/or authorized non- stormwater prior to filtration and discharge to surface waters. Clean Water Act (CWA) means the Federal Water Pollution Control Act enacted by Public Law 92-500, as amended by Public Laws 95-217, 95-576, 96-483, and 97-117; USC 1251 et seq. Combined Sewer means a sewer which has been designed to serve as a sanitary sewer and a storm sewer, and into which inflow is allowed by local ordinance. Construction Stormwater General Permit Page 48 Common Plan of Development or Sale means a site where multiple separate and distinct construction activities may be taking place at different times on different schedules and/or by different contractors, but still under a single plan. Examples include: 1) phased projects and projects with multiple filings or lots, even if the separate phases or filings/lots will be constructed under separate contract or by separate owners (e.g., a development where lots are sold to separate builders); 2) a development plan that may be phased over multiple years, but is still under a consistent plan for long-term development; 3) projects in a contiguous area that may be unrelated but still under the same contract, such as construction of a building extension and a new parking lot at the same facility; and 4) linear projects such as roads, pipelines, or utilities. If the project is part of a common plan of development or sale, the disturbed area of the entire plan must be used in determining permit requirements. Composite Sample means a mixture of grab samples collected at the same sampling point at different times, formed either by continuous sampling or by mixing discrete samples. May be "time-composite" (collected at constant time intervals) or "flow-proportional" (collected either as a constant sample volume at time intervals proportional to stream flow, or collected by increasing the volume of each aliquot as the flow increases while maintaining a constant time interval between the aliquots. Concrete Wastewater means any water used in the production, pouring and/or clean-up of concrete or concrete products, and any water used to cut, grind, wash, or otherwise modify concrete or concrete products. Examples include water used for or resulting from concrete truck/mixer/pumper/tool/chute rinsing or washing, concrete saw cutting and surfacing (sawing, coring, grinding, roughening, hydro-demolition, bridge and road surfacing). When stormwater comingles with concrete wastewater, the resulting water is considered concrete wastewater and must be managed to prevent discharge to waters of the State, including ground water. Construction Activity means land disturbing operations including clearing, grading or excavation which disturbs the surface of the land. Such activities may include road construction, construction of residential houses, office buildings, or industrial buildings, site preparation, soil compaction, movement and stockpiling of topsoils, and demolition activity. Contaminant means any hazardous substance that does not occur naturally or occurs at greater than natural background levels. See definition of hazardous substance and WAC 173-340-200. Contaminated Groundwater means groundwater which contains contaminants, pollutants, or hazardous substances that do not occur naturally or occur at levels greater than natural background. Contaminated Soil means soil which contains contaminants, pollutants, or hazardous substances that do not occur naturally or occur at levels greater than natural background. Demonstrably Equivalent means that the technical basis for the selection of all stormwater BMPs is documented within a SWPPP, including: 1. The method and reasons for choosing the stormwater BMPs selected. Construction Stormwater General Permit Page 49 2. The pollutant removal performance expected from the BMPs selected. 3. The technical basis supporting the performance claims for the BMPs selected, including any available data concerning field performance of the BMPs selected. 4. An assessment of how the selected BMPs will comply with state water quality standards. 5. An assessment of how the selected BMPs will satisfy both applicable federal technology- based treatment requirements and state requirements to use all known, available, and reasonable methods of prevention, control, and treatment (AKART). Department means the Washington State Department of Ecology. Detention means the temporary storage of stormwater to improve quality and/or to reduce the mass flow rate of discharge. Dewatering means the act of pumping ground water or stormwater away from an active construction site. Director means the Director of the Washington State Department of Ecology or his/her authorized representative. Discharger means an owner or operator of any facility or activity subject to regulation under Chapter 90.48 RCW or the Federal Clean Water Act. Domestic Wastewater means water carrying human wastes, including kitchen, bath, and laundry wastes from residences, buildings, industrial establishments, or other places, together with such ground water infiltration or surface waters as may be present. Ecology means the Washington State Department of Ecology. Engineered Soils means the use of soil amendments including, but not limited, to Portland cement treated base (CTB), cement kiln dust (CKD), or fly ash to achieve certain desirable soil characteristics. Equivalent BMPs means operational, source control, treatment, or innovative BMPs which result in equal or better quality of stormwater discharge to surface water or to ground water than BMPs selected from the SWMM. Erosion means the wearing away of the land surface by running water, wind, ice, or other geological agents, including such processes as gravitational creep. Erosion and Sediment Control BMPs means BMPs intended to prevent erosion and sedimentation, such as preserving natural vegetation, seeding, mulching and matting, plastic covering, filter fences, sediment traps, and ponds. Erosion and sediment control BMPs are synonymous with stabilization and structural BMPs. Federal Operator Operator any department, agency or instrumentality of the executive, legislative, and judicial branches of Construction Stormwater General Permit Page 50 the Federal government of the United States, or another entity, such as a private contractor, performing construction activity for any such department, agency, or instrumentality. Final Stabilization (same as fully stabilized or full stabilization) means the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures (examples of permanent non-vegetative stabilization methods include, but are not limited to riprap, gabions or geotextiles) which prevents erosion. Ground Water means water in a saturated zone or stratum beneath the land surface or a surface waterbody. Hazardous Substance means any dangerous or extremely hazardous waste as defined in RCW 70.105.010 (5) and (6), or any dangerous or extremely dangerous waste as designated by rule under chapter 70.105 RCW; any hazardous substance as defined in RCW 70.105.010(10) or any hazardous substance as defined by rule under chapter 70.105 RCW; any substance that, on the effective date of this section, is a hazardous substance under section 101(14) of the federal cleanup law, 42 U.S.C., Sec. 9601(14); petroleum or petroleum products; and any substance or category of substances, including solid waste decomposition products, determined by the director by rule to present a threat to human health or the environment if released into the environment. The term hazardous substance does not include any of the following when contained in an underground storage tank from which there is not a release: crude oil or any fraction thereof or petroleum, if the tank is in compliance with all applicable federal, state, and local law. Injection Well means a well that is used for the subsurface emplacement of fluids. (See Well.) Jurisdiction means a political unit such as a city, town or county; incorporated for local self- government. National Pollutant Discharge Elimination System (NPDES) means the national program for issuing, modifying, revoking and reissuing, terminating, monitoring, and enforcing permits, and imposing and enforcing pretreatment requirements, under sections 307, 402, 318, and 405 of the Federal Clean Water Act, for the discharge of pollutants to surface waters of the State from point sources. These permits are referred to as NPDES permits and, in Washington State, are administered by the Washington State Department of Ecology. Notice of Intent (NOI) means the application for, or a request for coverage under this general permit pursuant to WAC 173-226-200. Notice of Termination (NOT) means a request for termination of coverage under this general permit as specified by Special Condition S10 of this permit. Operator means any party associated with a construction project that meets either of the following two criteria: The party has operational control over construction plans and specifications, including the ability to make modifications to those plans and specifications; or Construction Stormwater General Permit Page 51 The party has day-to-day operational control of those activities at a project that are necessary to ensure compliance with a SWPPP for the site or other permit conditions (e.g., they are authorized to direct workers at a site to carry out activities required by the SWPPP or comply with other permit conditions). Permittee means individual or entity that receives notice of coverage under this general permit. pH . A pH of 7 is defined as neutral. Large variations above or below this value are considered harmful to most aquatic life. pH Monitoring Period means the time period in which the pH of stormwater runoff from a site must be tested a minimum of once every seven days to determine if stormwater pH is between 6.5 and 8.5. Point Source means any discernible, confined, and discrete conveyance, including but not limited to, any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, and container from which pollutants are or may be discharged to surface waters of the State. This term does not include return flows from irrigated agriculture. (See Fact Sheet for further explanation.) Pollutant means dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, domestic sewage sludge (biosolids), munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal, and agricultural waste. This term does not include sewage from vessels within the meaning of section 312 of the CWA, nor does it include dredged or fill material discharged in accordance with a permit issued under section 404 of the CWA. Pollution means contamination or other alteration of the physical, chemical, or biological properties of waters of the State; including change in temperature, taste, color, turbidity, or odor of the waters; or such discharge of any liquid, gaseous, solid, radioactive or other substance into any waters of the State as will or is likely to create a nuisance or render such waters harmful, detrimental or injurious to the public health, safety or welfare; or to domestic, commercial, industrial, agricultural, recreational, or other legitimate beneficial uses; or to livestock, wild animals, birds, fish or other aquatic life. Process Wastewater means any water which, during manufacturing or processing, comes into direct contact with or results from the production or use of any raw material, intermediate product, finished product, byproduct, or waste product. If stormwater commingles with process wastewater, the commingled water is considered process wastewater. Receiving Water means the waterbody at the point of discharge. If the discharge is to a storm sewer system, either surface or subsurface, the receiving water is the waterbody to which the storm system discharges. Systems designed primarily for other purposes such as for ground water drainage, redirecting stream natural flows, or for conveyance of irrigation water/return flows that coincidentally convey stormwater are considered the receiving water. Construction Stormwater General Permit Page 52 Representative means a stormwater or wastewater sample which represents the flow and characteristics of the discharge. Representative samples may be a grab sample, a time- proportionate composite sample, or a flow proportionate sample. Stormwater Monitoring Manual provides guidance on representative sampling. Responsible Corporate Officer for the purpose of signatory authority means: (i) a president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision-making functions for the corporation, or (ii) the manager of one or more manufacturing, production, or operating facilities, provided, the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for permit application requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures (40 CFR 122.22). Sanitary Sewer means a sewer which is designed to convey domestic wastewater. Sediment means the fragmented material that originates from the weathering and erosion of rocks or unconsolidated deposits, and is transported by, suspended in, or deposited by water. Sedimentation means the depositing or formation of sediment. Sensitive Area means a waterbody, wetland, stream, aquifer recharge area, or channel migration zone. SEPA (State Environmental Policy Act) means the Washington State Law, RCW 43.21C.020, intended to prevent or eliminate damage to the environment. Significant Amount means an amount of a pollutant in a discharge that is amenable to available and reasonable methods of prevention or treatment; or an amount of a pollutant that has a reasonable potential to cause a violation of surface or ground water quality or sediment management standards. Significant Concrete Work means greater than 1000 cubic yards poured concrete or recycled concrete used over the life of a project. Significant Contributor of Pollutants means a facility determined by Ecology to be a contributor of a significant amount(s) of a pollutant(s) to waters of the State of Washington. Site means the land or water area where any "facility or activity" is physically located or conducted. Source Control BMPs means physical, structural or mechanical devices or facilities that are intended to prevent pollutants from entering stormwater. A few examples of source control Construction Stormwater General Permit Page 53 BMPs are erosion control practices, maintenance of stormwater facilities, constructing roofs over storage and working areas, and directing wash water and similar discharges to the sanitary sewer or a dead end sump. Stabilization means the application of appropriate BMPs to prevent the erosion of soils, such as, temporary and permanent seeding, vegetative covers, mulching and matting, plastic covering and sodding. See also the definition of Erosion and Sediment Control BMPs. Storm Drain means any drain which drains directly into a storm sewer system, usually found along roadways or in parking lots. Storm Sewer System means a means a conveyance, or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm drains designed or used for collecting or conveying stormwater. This does not include systems which are part of a combined sewer or Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2. Stormwater means that portion of precipitation that does not naturally percolate into the ground or evaporate, but flows via overland flow, interflow, pipes, and other features of a stormwater drainage system into a defined surface waterbody, or a constructed infiltration facility. Stormwater Management Manual (SWMM) or Manual means the technical Manual published by Ecology for use by local governments that contain descriptions of and design criteria for BMPs to prevent, control, or treat pollutants in stormwater. Stormwater Pollution Prevention Plan (SWPPP) means a documented plan to implement measures to identify, prevent, and control the contamination of point source discharges of stormwater. Surface Waters of the State includes lakes, rivers, ponds, streams, inland waters, salt waters, and all other surface waters and water courses within the jurisdiction of the State of Washington. Temporary Stabilization means the exposed ground surface has been covered with appropriate materials to provide temporary stabilization of the surface from water or wind erosion. Materials include, but are not limited to, mulch, riprap, erosion control mats or blankets and temporary cover crops. Seeding alone is not considered stabilization. Temporary stabilization is not a final stabilization Total Maximum Daily Load (TMDL) means a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet state water quality standards. Percentages of the total maximum daily load are allocated to the various pollutant sources. A TMDL is the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources. The TMDL calculations must include a "margin of safety" to ensure that the waterbody can be protected in case there are unforeseen events or unknown sources of the pollutant. The calculation must also account for seasonable variation in water quality. Construction Stormwater General Permit Page 54 Transfer of Coverage (TOC) means a request for transfer of coverage under this general permit as specified by General Condition G9 of this permit. Treatment BMPs means BMPs that are intended to remove pollutants from stormwater. A few examples of treatment BMPs are detention ponds, oil/water separators, biofiltration, and constructed wetlands. Transparency means a measurement of water clarity in centimeters (cm), using a 60 cm transparency tube. The transparency tube is used to estimate the relative clarity or transparency of water by noting the depth at which a black and white Secchi disc becomes visible when water is released from a value in the bottom of the tube. A transparency tube is sometimes referred to turbidity t Turbidity means the clarity of water expressed as nephelometric turbidity units (NTUs) and measured with a calibrated turbidimeter. Uncontaminated means free from any contaminant. contaminant WAC 173-340-200. Waste Load Allocation (WLA) is allocated to one of its existing or future point sources of pollution. WLAs constitute a type of water quality based effluent limitation (40 CFR 130.2[h]). Water-only Based Shaft Drilling is a shaft drilling process that uses water only and no additives are involved in the drilling of shafts for construction of building, road, or bridge foundations. Water quality means the chemical, physical, and biological characteristics of water, usually with respect to its suitability for a particular purpose. Waters of the State includes those waters as defined as "waters of the United States" in 40 CFR Subpart 122.2 within the geographic boundaries of Washington State and "waters of the State" as defined in Chapter 90.48 RCW, which include lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all other surface waters and water courses within the jurisdiction of the state of Washington. Well means a bored, drilled or driven shaft, or dug hole whose depth is greater than the largest surface dimension. (See Injection well.) Wheel Wash Wastewater means any water used in, or resulting from the operation of, a tire bath or wheel wash (BMP C106: Wheel Wash), or other structure or practice that uses water to physically remove mud and debris from vehicles leaving a construction site and prevent track- out onto roads. When stormwater comingles with wheel wash wastewater, the resulting water is considered wheel wash wastewater and must be managed according to Special Condition S9.D.9. Construction Stormwater General Permit Page 55 APPENDIX B ACRONYMS AKART All Known, Available, and Reasonable Methods of Prevention, Control, and Treatment BMP Best Management Practice CESCL Certified Erosion and Sediment Control Lead CFR Code of Federal Regulations CKD Cement Kiln Dust cm Centimeters CTB Cement-Treated Base CWA Clean Water Act DMR Discharge Monitoring Report EPA Environmental Protection Agency ERTS Environmental Report Tracking System ESC Erosion and Sediment Control FR Federal Register LID Low Impact Development NOI Notice of Intent NOT Notice of Termination NPDES National Pollutant Discharge Elimination System NTU Nephelometric Turbidity Unit RCW Revised Code of Washington SEPA State Environmental Policy Act SWMM Stormwater Management Manual SWPPP Stormwater Pollution Prevention Plan TMDL Total Maximum Daily Load UIC Underground Injection Control USC United States Code USEPA United States Environmental Protection Agency WAC Washington Administrative Code WQ Water Quality WWHM Western Washington Hydrology Model WWHM2012 PROJECT REPORT 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 2 General Model Information Project Name:18615 - .5 infiltration Site Name: Site Address: City: Report Date:6/13/2019 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:0.000 (adjusted) Version Date:2018/10/10 Version:4.2.16 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 1.7882 Pervious Total 1.7882 Impervious Land Use acre Impervious Total 0 Basin Total 1.7882 Element Flows To: Surface Interflow Groundwater 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 4 Mitigated Land Use Basin 1 (Building) Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROOF TOPS FLAT 0.2428 Impervious Total 0.2428 Basin Total 0.2428 Element Flows To: Surface Interflow Groundwater DETENTION/INFILTRATION VAULTDETENTION/INFILTRATION VAULT 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 5 Basin 3: Building & Site Bypass:No GroundWater:No Pervious Land Use acre C, Pasture, Mod 0.7605 Pervious Total 0.7605 Impervious Land Use acre ROADS MOD 0.3538 ROOF TOPS FLAT 0.1653 SIDEWALKS MOD 0.2026 Impervious Total 0.7217 Basin Total 1.4822 Element Flows To: Surface Interflow Groundwater DETENTION/INFILTRATION VAULTDETENTION/INFILTRATION VAULT 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 6 Basin 2: Building 2 Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROOF TOPS FLAT 0.0633 Impervious Total 0.0633 Basin Total 0.0633 Element Flows To: Surface Interflow Groundwater DETENTION/INFILTRATION VAULTDETENTION/INFILTRATION VAULT 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 7 Routing Elements Predeveloped Routing 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 8 Mitigated Routing DETENTION/INFILTRATION VAULT Width:36 ft. Length:72 ft. Depth:5.9 ft. Infiltration On Infiltration rate:0.5 Infiltration safety factor:1 Total Volume Infiltrated (ac-ft.):140.39 Total Volume Through Riser (ac-ft.):62.181 Total Volume Through Facility (ac-ft.):202.571 Percent Infiltrated:69.3 Total Precip Applied to Facility:0 Total Evap From Facility:0 Discharge Structure Riser Height:4.9 ft. Riser Diameter:12 in. Notch Type:Rectangular Notch Width:0.012 ft. Notch Height:0.250 ft. Orifice 1 Diameter:1.0625 in.Elevation:0 ft. Orifice 2 Diameter:1.125 in.Elevation:2.9 ft. Element Flows To: Outlet 1 Outlet 2 Vault Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.059 0.000 0.000 0.000 0.0656 0.059 0.003 0.007 0.030 0.1311 0.059 0.007 0.011 0.030 0.1967 0.059 0.011 0.013 0.030 0.2622 0.059 0.015 0.015 0.030 0.3278 0.059 0.019 0.017 0.030 0.3933 0.059 0.023 0.019 0.030 0.4589 0.059 0.027 0.020 0.030 0.5244 0.059 0.031 0.022 0.030 0.5900 0.059 0.035 0.023 0.030 0.6556 0.059 0.039 0.024 0.030 0.7211 0.059 0.042 0.026 0.030 0.7867 0.059 0.046 0.027 0.030 0.8522 0.059 0.050 0.028 0.030 0.9178 0.059 0.054 0.029 0.030 0.9833 0.059 0.058 0.030 0.030 1.0489 0.059 0.062 0.031 0.030 1.1144 0.059 0.066 0.032 0.030 1.1800 0.059 0.070 0.033 0.030 1.2456 0.059 0.074 0.034 0.030 1.3111 0.059 0.078 0.035 0.030 1.3767 0.059 0.081 0.035 0.030 1.4422 0.059 0.085 0.036 0.030 1.5078 0.059 0.089 0.037 0.030 1.5733 0.059 0.093 0.038 0.030 1.6389 0.059 0.097 0.039 0.030 1.7044 0.059 0.101 0.040 0.030 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 9 1.7700 0.059 0.105 0.040 0.030 1.8356 0.059 0.109 0.041 0.030 1.9011 0.059 0.113 0.042 0.030 1.9667 0.059 0.117 0.043 0.030 2.0322 0.059 0.120 0.043 0.030 2.0978 0.059 0.124 0.044 0.030 2.1633 0.059 0.128 0.045 0.030 2.2289 0.059 0.132 0.045 0.030 2.2944 0.059 0.136 0.046 0.030 2.3600 0.059 0.140 0.047 0.030 2.4256 0.059 0.144 0.047 0.030 2.4911 0.059 0.148 0.048 0.030 2.5567 0.059 0.152 0.049 0.030 2.6222 0.059 0.156 0.049 0.030 2.6878 0.059 0.159 0.050 0.030 2.7533 0.059 0.163 0.050 0.030 2.8189 0.059 0.167 0.051 0.030 2.8844 0.059 0.171 0.052 0.030 2.9500 0.059 0.175 0.060 0.030 3.0156 0.059 0.179 0.064 0.030 3.0811 0.059 0.183 0.068 0.030 3.1467 0.059 0.187 0.071 0.030 3.2122 0.059 0.191 0.074 0.030 3.2778 0.059 0.195 0.076 0.030 3.3433 0.059 0.198 0.078 0.030 3.4089 0.059 0.202 0.081 0.030 3.4744 0.059 0.206 0.083 0.030 3.5400 0.059 0.210 0.085 0.030 3.6056 0.059 0.214 0.087 0.030 3.6711 0.059 0.218 0.088 0.030 3.7367 0.059 0.222 0.090 0.030 3.8022 0.059 0.226 0.092 0.030 3.8678 0.059 0.230 0.094 0.030 3.9333 0.059 0.234 0.095 0.030 3.9989 0.059 0.238 0.097 0.030 4.0644 0.059 0.241 0.098 0.030 4.1300 0.059 0.245 0.100 0.030 4.1956 0.059 0.249 0.101 0.030 4.2611 0.059 0.253 0.103 0.030 4.3267 0.059 0.257 0.104 0.030 4.3922 0.059 0.261 0.106 0.030 4.4578 0.059 0.265 0.107 0.030 4.5233 0.059 0.269 0.108 0.030 4.5889 0.059 0.273 0.110 0.030 4.6544 0.059 0.277 0.111 0.030 4.7200 0.059 0.280 0.113 0.030 4.7856 0.059 0.284 0.116 0.030 4.8511 0.059 0.288 0.118 0.030 4.9167 0.059 0.292 0.144 0.030 4.9822 0.059 0.296 0.371 0.030 5.0478 0.059 0.300 0.715 0.030 5.1133 0.059 0.304 1.115 0.030 5.1789 0.059 0.308 1.516 0.030 5.2444 0.059 0.312 1.864 0.030 5.3100 0.059 0.316 2.121 0.030 5.3756 0.059 0.319 2.286 0.030 5.4411 0.059 0.323 2.447 0.030 5.5067 0.059 0.327 2.585 0.030 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 10 5.5722 0.059 0.331 2.715 0.030 5.6378 0.059 0.335 2.839 0.030 5.7033 0.059 0.339 2.958 0.030 5.7689 0.059 0.343 3.072 0.030 5.8344 0.059 0.347 3.182 0.030 5.9000 0.059 0.351 3.288 0.030 5.9656 0.059 0.355 3.390 0.030 6.0311 0.000 0.000 3.490 0.000 18615 - .5 infiltration 6/13/2019 6:50:09 AM Page 11 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:1.7882 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.7605 Total Impervious Area:1.0278 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.053244 5 year 0.087245 10 year 0.109107 25 year 0.135113 50 year 0.153126 100 year 0.169951 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.042264 5 year 0.062389 10 year 0.078793 25 year 0.103469 50 year 0.125023 100 year 0.149566 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.061 0.037 1950 0.073 0.042 1951 0.116 0.093 1952 0.036 0.033 1953 0.029 0.033 1954 0.045 0.035 1955 0.072 0.048 1956 0.058 0.042 1957 0.047 0.040 1958 0.052 0.040 18615 - .5 infiltration 6/13/2019 6:50:53 AM Page 12 1959 0.045 0.035 1960 0.080 0.085 1961 0.044 0.038 1962 0.027 0.029 1963 0.038 0.037 1964 0.053 0.037 1965 0.036 0.040 1966 0.034 0.030 1967 0.082 0.045 1968 0.046 0.032 1969 0.045 0.039 1970 0.036 0.035 1971 0.041 0.038 1972 0.088 0.052 1973 0.039 0.034 1974 0.043 0.030 1975 0.060 0.046 1976 0.043 0.035 1977 0.006 0.030 1978 0.037 0.039 1979 0.022 0.029 1980 0.104 0.049 1981 0.033 0.033 1982 0.067 0.085 1983 0.058 0.042 1984 0.035 0.033 1985 0.021 0.037 1986 0.091 0.074 1987 0.081 0.082 1988 0.032 0.033 1989 0.021 0.023 1990 0.193 0.076 1991 0.102 0.091 1992 0.042 0.034 1993 0.041 0.037 1994 0.014 0.022 1995 0.058 0.042 1996 0.135 0.091 1997 0.104 0.098 1998 0.026 0.032 1999 0.114 0.059 2000 0.041 0.036 2001 0.007 0.027 2002 0.047 0.072 2003 0.070 0.029 2004 0.075 0.162 2005 0.056 0.045 2006 0.063 0.041 2007 0.146 0.097 2008 0.178 0.116 2009 0.083 0.051 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.1928 0.1617 2 0.1776 0.1156 3 0.1457 0.0984 18615 - .5 infiltration 6/13/2019 6:50:53 AM Page 13 4 0.1350 0.0973 5 0.1163 0.0931 6 0.1143 0.0912 7 0.1042 0.0910 8 0.1040 0.0855 9 0.1023 0.0846 10 0.0912 0.0822 11 0.0883 0.0761 12 0.0828 0.0739 13 0.0818 0.0721 14 0.0805 0.0587 15 0.0803 0.0516 16 0.0751 0.0510 17 0.0727 0.0493 18 0.0724 0.0478 19 0.0703 0.0464 20 0.0674 0.0450 21 0.0627 0.0447 22 0.0613 0.0423 23 0.0604 0.0418 24 0.0584 0.0417 25 0.0583 0.0416 26 0.0577 0.0414 27 0.0557 0.0404 28 0.0535 0.0402 29 0.0522 0.0396 30 0.0471 0.0387 31 0.0470 0.0385 32 0.0460 0.0384 33 0.0453 0.0378 34 0.0448 0.0372 35 0.0448 0.0371 36 0.0441 0.0370 37 0.0434 0.0368 38 0.0432 0.0366 39 0.0418 0.0355 40 0.0408 0.0354 41 0.0406 0.0353 42 0.0406 0.0352 43 0.0391 0.0347 44 0.0377 0.0340 45 0.0365 0.0335 46 0.0365 0.0335 47 0.0360 0.0333 48 0.0355 0.0333 49 0.0347 0.0332 50 0.0342 0.0327 51 0.0326 0.0324 52 0.0318 0.0321 53 0.0295 0.0301 54 0.0275 0.0300 55 0.0255 0.0297 56 0.0221 0.0291 57 0.0210 0.0289 58 0.0206 0.0285 59 0.0137 0.0271 60 0.0073 0.0230 61 0.0063 0.0223 18615 - .5 infiltration 6/13/2019 6:50:53 AM Page 14 18615 - .5 infiltration 6/13/2019 6:50:53 AM Page 15 Duration Flows The Facility PASSED Flow(cfs)Predev Mit Percentage Pass/Fail 0.0266 17077 17128 100 Pass 0.0279 15494 15180 97 Pass 0.0292 14072 13533 96 Pass 0.0305 12799 11965 93 Pass 0.0317 11567 10525 90 Pass 0.0330 10515 9240 87 Pass 0.0343 9567 8104 84 Pass 0.0356 8752 7099 81 Pass 0.0368 8031 6252 77 Pass 0.0381 7347 5414 73 Pass 0.0394 6731 4765 70 Pass 0.0407 6192 4282 69 Pass 0.0420 5730 3814 66 Pass 0.0432 5309 3392 63 Pass 0.0445 4924 2939 59 Pass 0.0458 4569 2603 56 Pass 0.0471 4235 2257 53 Pass 0.0483 3951 1943 49 Pass 0.0496 3643 1602 43 Pass 0.0509 3388 1329 39 Pass 0.0522 3133 1111 35 Pass 0.0535 2915 1078 36 Pass 0.0547 2706 1057 39 Pass 0.0560 2488 1037 41 Pass 0.0573 2314 1018 43 Pass 0.0586 2136 998 46 Pass 0.0598 1972 982 49 Pass 0.0611 1822 963 52 Pass 0.0624 1702 943 55 Pass 0.0637 1577 924 58 Pass 0.0650 1442 900 62 Pass 0.0662 1325 878 66 Pass 0.0675 1232 847 68 Pass 0.0688 1147 818 71 Pass 0.0701 1085 787 72 Pass 0.0713 1020 753 73 Pass 0.0726 947 712 75 Pass 0.0739 885 677 76 Pass 0.0752 824 637 77 Pass 0.0765 760 595 78 Pass 0.0777 725 562 77 Pass 0.0790 674 524 77 Pass 0.0803 623 488 78 Pass 0.0816 589 440 74 Pass 0.0828 549 397 72 Pass 0.0841 506 367 72 Pass 0.0854 469 331 70 Pass 0.0867 427 307 71 Pass 0.0880 388 285 73 Pass 0.0892 356 255 71 Pass 0.0905 328 229 69 Pass 0.0918 297 197 66 Pass 0.0931 270 178 65 Pass 18615 - .5 infiltration 6/13/2019 6:50:53 AM Page 16 0.0943 241 166 68 Pass 0.0956 218 146 66 Pass 0.0969 197 126 63 Pass 0.0982 173 108 62 Pass 0.0995 152 97 63 Pass 0.1007 130 91 70 Pass 0.1020 119 84 70 Pass 0.1033 106 78 73 Pass 0.1046 95 72 75 Pass 0.1058 84 65 77 Pass 0.1071 74 61 82 Pass 0.1084 69 55 79 Pass 0.1097 61 49 80 Pass 0.1110 54 43 79 Pass 0.1122 46 38 82 Pass 0.1135 39 32 82 Pass 0.1148 31 28 90 Pass 0.1161 25 16 64 Pass 0.1173 22 12 54 Pass 0.1186 20 9 45 Pass 0.1199 17 9 52 Pass 0.1212 14 8 57 Pass 0.1225 12 8 66 Pass 0.1237 8 8 100 Pass 0.1250 7 7 100 Pass 0.1263 7 7 100 Pass 0.1276 7 6 85 Pass 0.1288 6 6 100 Pass 0.1301 6 5 83 Pass 0.1314 6 5 83 Pass 0.1327 6 5 83 Pass 0.1340 6 5 83 Pass 0.1352 5 4 80 Pass 0.1365 5 4 80 Pass 0.1378 5 4 80 Pass 0.1391 5 4 80 Pass 0.1403 5 4 80 Pass 0.1416 5 4 80 Pass 0.1429 5 4 80 Pass 0.1442 4 3 75 Pass 0.1455 4 2 50 Pass 0.1467 3 2 66 Pass 0.1480 3 2 66 Pass 0.1493 3 2 66 Pass 0.1506 3 2 66 Pass 0.1518 3 2 66 Pass 0.1531 3 2 66 Pass 18615 - .5 infiltration 6/13/2019 6:50:53 AM Page 17 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.1417 acre-feet On-line facility target flow:0.1725 cfs. Adjusted for 15 min:0.1725 cfs. Off-line facility target flow:0.0963 cfs. Adjusted for 15 min:0.0963 cfs. 18615 - .5 infiltration 6/13/2019 6:50:53 AM Page 18 LID Report 18615 - .5 infiltration 6/13/2019 6:51:16 AM Page 19 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. 18615 - .5 infiltration 6/13/2019 6:51:16 AM Page 20 Appendix Predeveloped Schematic 18615 - .5 infiltration 6/13/2019 6:51:17 AM Page 21 Mitigated Schematic 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 22 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 18615 - .5 infiltration.wdm MESSU 25 Pre18615 - .5 infiltration.MES 27 Pre18615 - .5 infiltration.L61 28 Pre18615 - .5 infiltration.L62 30 POC18615 - .5 infiltration1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 11 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 11 C, Forest, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 11 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 11 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 23 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 11 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 11 0 4.5 0.08 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 11 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 11 0.2 0.5 0.35 6 0.5 0.7 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 11 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATE1 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 24 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 11 1.7882 COPY 501 12 PERLND 11 1.7882 COPY 501 13 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 25 WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 END MASS-LINK END RUN 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 26 Mitigated UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 18615 - .5 infiltration.wdm MESSU 25 Mit18615 - .5 infiltration.MES 27 Mit18615 - .5 infiltration.L61 28 Mit18615 - .5 infiltration.L62 30 POC18615 - .5 infiltration1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 IMPLND 4 PERLND 14 IMPLND 2 IMPLND 9 RCHRES 1 COPY 1 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 DETENTION/INFILTRATION VA MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 14 C, Pasture, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 14 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 27 <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 14 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 14 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 14 0 4.5 0.06 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 14 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 14 0.15 0.4 0.3 6 0.5 0.4 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 14 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 4 ROOF TOPS/FLAT 1 1 1 27 0 2 ROADS/MOD 1 1 1 27 0 9 SIDEWALKS/MOD 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 4 0 0 1 0 0 0 2 0 0 1 0 0 0 9 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 4 0 0 4 0 0 0 1 9 2 0 0 4 0 0 0 1 9 9 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 4 0 0 0 0 0 2 0 0 0 0 0 9 0 0 0 0 0 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 28 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 4 400 0.01 0.1 0.1 2 400 0.05 0.1 0.08 9 400 0.05 0.1 0.08 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 4 0 0 2 0 0 9 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 4 0 0 2 0 0 9 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1 (Building)*** IMPLND 4 0.2428 RCHRES 1 5 Basin 3: Building & Site*** PERLND 14 0.7605 RCHRES 1 2 PERLND 14 0.7605 RCHRES 1 3 IMPLND 2 0.3538 RCHRES 1 5 IMPLND 4 0.1653 RCHRES 1 5 IMPLND 9 0.2026 RCHRES 1 5 Basin 2: Building 2*** IMPLND 4 0.0633 RCHRES 1 5 ******Routing****** IMPLND 4 0.2428 COPY 1 15 PERLND 14 0.7605 COPY 1 12 IMPLND 2 0.3538 COPY 1 15 IMPLND 4 0.1653 COPY 1 15 IMPLND 9 0.2026 COPY 1 15 PERLND 14 0.7605 COPY 1 13 IMPLND 4 0.0633 COPY 1 15 RCHRES 1 1 COPY 501 17 END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** 1 DETENTION/INFILT-011 2 1 1 1 28 0 1 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 29 END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** 1 0 1 0 0 4 5 0 0 0 0 0 0 0 0 2 2 2 2 2 END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** 1 1 0.01 0.0 0.0 0.5 0.0 END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES FTABLE 1 92 5 Depth Area Volume Outflow1 Outflow2 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)*** 0.000000 0.059504 0.000000 0.000000 0.000000 0.065556 0.059504 0.003901 0.007844 0.030000 0.131111 0.059504 0.007802 0.011093 0.030000 0.196667 0.059504 0.011702 0.013586 0.030000 0.262222 0.059504 0.015603 0.015687 0.030000 0.327778 0.059504 0.019504 0.017539 0.030000 0.393333 0.059504 0.023405 0.019213 0.030000 0.458889 0.059504 0.027306 0.020752 0.030000 0.524444 0.059504 0.031207 0.022185 0.030000 0.590000 0.059504 0.035107 0.023531 0.030000 0.655556 0.059504 0.039008 0.024804 0.030000 0.721111 0.059504 0.042909 0.026015 0.030000 0.786667 0.059504 0.046810 0.027171 0.030000 0.852222 0.059504 0.050711 0.028281 0.030000 0.917778 0.059504 0.054612 0.029348 0.030000 0.983333 0.059504 0.058512 0.030379 0.030000 1.048889 0.059504 0.062413 0.031375 0.030000 1.114444 0.059504 0.066314 0.032340 0.030000 1.180000 0.059504 0.070215 0.033278 0.030000 1.245556 0.059504 0.074116 0.034190 0.030000 1.311111 0.059504 0.078017 0.035078 0.030000 1.376667 0.059504 0.081917 0.035944 0.030000 1.442222 0.059504 0.085818 0.036790 0.030000 1.507778 0.059504 0.089719 0.037617 0.030000 1.573333 0.059504 0.093620 0.038426 0.030000 1.638889 0.059504 0.097521 0.039219 0.030000 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 30 1.704444 0.059504 0.101421 0.039995 0.030000 1.770000 0.059504 0.105322 0.040757 0.030000 1.835556 0.059504 0.109223 0.041505 0.030000 1.901111 0.059504 0.113124 0.042240 0.030000 1.966667 0.059504 0.117025 0.042962 0.030000 2.032222 0.059504 0.120926 0.043672 0.030000 2.097778 0.059504 0.124826 0.044371 0.030000 2.163333 0.059504 0.128727 0.045059 0.030000 2.228889 0.059504 0.132628 0.045736 0.030000 2.294444 0.059504 0.136529 0.046404 0.030000 2.360000 0.059504 0.140430 0.047062 0.030000 2.425556 0.059504 0.144331 0.047711 0.030000 2.491111 0.059504 0.148231 0.048352 0.030000 2.556667 0.059504 0.152132 0.048984 0.030000 2.622222 0.059504 0.156033 0.049608 0.030000 2.687778 0.059504 0.159934 0.050224 0.030000 2.753333 0.059504 0.163835 0.050833 0.030000 2.818889 0.059504 0.167736 0.051435 0.030000 2.884444 0.059504 0.171636 0.052029 0.030000 2.950000 0.059504 0.175537 0.060297 0.030000 3.015556 0.059504 0.179438 0.064874 0.030000 3.081111 0.059504 0.183339 0.068390 0.030000 3.146667 0.059504 0.187240 0.071400 0.030000 3.212222 0.059504 0.191140 0.074097 0.030000 3.277778 0.059504 0.195041 0.076573 0.030000 3.343333 0.059504 0.198942 0.078883 0.030000 3.408889 0.059504 0.202843 0.081062 0.030000 3.474444 0.059504 0.206744 0.083134 0.030000 3.540000 0.059504 0.210645 0.085115 0.030000 3.605556 0.059504 0.214545 0.087019 0.030000 3.671111 0.059504 0.218446 0.088856 0.030000 3.736667 0.059504 0.222347 0.090634 0.030000 3.802222 0.059504 0.226248 0.092359 0.030000 3.867778 0.059504 0.230149 0.094036 0.030000 3.933333 0.059504 0.234050 0.095670 0.030000 3.998889 0.059504 0.237950 0.097264 0.030000 4.064444 0.059504 0.241851 0.098823 0.030000 4.130000 0.059504 0.245752 0.100348 0.030000 4.195556 0.059504 0.249653 0.101842 0.030000 4.261111 0.059504 0.253554 0.103307 0.030000 4.326667 0.059504 0.257455 0.104745 0.030000 4.392222 0.059504 0.261355 0.106158 0.030000 4.457778 0.059504 0.265256 0.107547 0.030000 4.523333 0.059504 0.269157 0.108914 0.030000 4.588889 0.059504 0.273058 0.110259 0.030000 4.654444 0.059504 0.276959 0.111596 0.030000 4.720000 0.059504 0.280860 0.113620 0.030000 4.785556 0.059504 0.284760 0.116118 0.030000 4.851111 0.059504 0.288661 0.118907 0.030000 4.916667 0.059504 0.292562 0.144281 0.030000 4.982222 0.059504 0.296463 0.371938 0.030000 5.047778 0.059504 0.300364 0.715787 0.030000 5.113333 0.059504 0.304264 1.115779 0.030000 5.178889 0.059504 0.308165 1.516327 0.030000 5.244444 0.059504 0.312066 1.864028 0.030000 5.310000 0.059504 0.315967 2.121277 0.030000 5.375556 0.059504 0.319868 2.286300 0.030000 5.441111 0.059504 0.323769 2.447830 0.030000 5.506667 0.059504 0.327669 2.585294 0.030000 5.572222 0.059504 0.331570 2.715559 0.030000 5.637778 0.059504 0.335471 2.839656 0.030000 5.703333 0.059504 0.339372 2.958389 0.030000 5.768889 0.059504 0.343273 3.072401 0.030000 5.834444 0.059504 0.347174 3.182219 0.030000 5.900000 0.059504 0.351074 3.288275 0.030000 5.965556 0.059504 0.354975 3.390932 0.030000 END FTABLE 1 END FTABLES EXT SOURCES 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 31 <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1004 FLOW ENGL REPL RCHRES 1 HYDR O 1 1 1 WDM 1005 FLOW ENGL REPL RCHRES 1 HYDR O 2 1 1 WDM 1006 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1007 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 2 PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 2 MASS-LINK 3 PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 3 MASS-LINK 5 IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 5 MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 MASS-LINK 17 RCHRES OFLOW OVOL 1 COPY INPUT MEAN END MASS-LINK 17 END MASS-LINK END RUN 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 32 Predeveloped HSPF Message File 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 33 Mitigated HSPF Message File 18615 - .5 infiltration 6/13/2019 6:51:19 AM Page 34 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2019; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com